Previous Article | Next Article 
Journal of Bacteriology, August 2004, p. 5197-5201, Vol. 186, No. 16
0021-9193/04/$08.00+0 DOI: 10.1128/JB.186.16.5197-5201.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.
Phosphate Control of the Biosynthesis of Antibiotics and Other Secondary Metabolites Is Mediated by the PhoR-PhoP System: an Unfinished Story
Juan F. Martín*
Area of Microbiology, University of León, and Institute of Biotechnology, Science Park of León, 24006, León, Spain

INTRODUCTION
The biosynthesis of many different types of antibiotics and
other secondary metabolites is regulated by phosphate. Production
of these valuable compounds occurs only under phosphate-limiting
nutritional conditions. In a few cases, there is evidence showing
that the negative phosphate control is exerted at the transcriptional
level. Recently, it was shown that phosphate control of antibiotic
biosynthesis in
Streptomyces lividans and
Streptomyces coelicolor is mediated by the two-component PhoR-PhoP system that also
controls the alkaline phosphatase gene (
phoA). The PhoR protein
is a standard membrane sensor kinase, whereas PhoP is a member
of the DNA-binding response regulators. In
Escherichia coli and
Bacillus subtilis, the phosphorylated PhoP protein (PhoP

P)
activates, in response to phosphate starvation, expression of
the
pho regulon genes by binding to consensus phosphate boxes
in the promoter regions (PHO boxes). Expression of
phoA in
S. lividans is induced by PhoP

P, and mutants lacking
phoP (or
phoR and
phoP) do not form PhoA. These mutants overproduce large
amounts of actinorhodin and undecylprodigiosin. No consensus
PHO boxes occur in the upstream region of phosphate-regulated
secondary metabolism genes. However, pathway-specific activator
proteins (ActII-open reading frame 4 [ORF4], RedD, CcaR, and
DnrI) are known to bind to these regions. In
S. coelicolor,
actII-orf4 is positively regulated by the AfsS protein, which,
in turn, is induced by the phosphorylated AfsR protein. It is
likely that the PhoR-PhoP system exerts its action on actinorhodin
and undecylprodigiosin by a cascade mechanism mediated by AfsR
and AfsS. Directed
phoR-phoP gene disruption will be very useful
for the construction of tailored phosphate-deregulated strains
overproducing valuable secondary metabolites.

PHOSPHATE CONTROL OF ANTIBIOTIC BIOSYNTHESIS: HISTORICAL PERSPECTIVE
The negative control exerted by inorganic phosphate on the biosynthesis
of antibiotics and other secondary metabolites has been known
for many years. Over the last four decades, an impressive number
of antibiotics and secondary metabolites have been shown to
be regulated negatively by phosphate. These include streptomycin,
oxytetracycline, clavulanic acid, tylosin, echinomycin, cephalosporin,
cephamycin C, and thienamycin, among many other secondary metabolites
(
23,
27,
32), but, surprisingly, the molecular mechanism of
phosphate control has remained obscure (
30) in spite of its
basic and industrial relevance. It is interesting that inorganic
phosphate in the culture medium controls the synthesis of a
large number of secondary metabolites belonging to different
biosynthetic groups such as, for example, macrolides, tetracyclines,
anthracyclines, polyether compounds, aminoglycosides, and amino
acid-derived metabolites such as clavulanic acid, among others
(
10,
11,
15,
16,
25). Why are all these compounds repressed
by high concentrations of inorganic phosphate? From a biosynthetic
point of view, these groups of metabolites have very little
in common, except that they all are dispensable "secondary"
metabolites. The negative effect exerted by inorganic phosphate
on the biosynthesis of secondary metabolites is observed in
a wide range of microorganisms, including proteobacteria, gram-positive
bacteria (e.g., actinomycetes), and filamentous fungi, and probably
has a wide ecological role. Martín and Demain proposed
that phosphate control is used as a mechanism that triggers
secondary metabolite biosynthesis when phosphate in the environment
is depleted and, therefore, growth of the microorganisms cannot
proceed at a normal rate (
28). When the phosphate concentration
in the culture medium decreases below a threshold level, bacteria
increase their production of a variety of metabolites that might
serve as direct antagonists to other microorganisms (
48) or
as biochemical cross talk signals (
17,
38,
51) to enhance survival
under harsh nutritional conditions (
26).
A number of scientific studies published since the 1970s describe the negative effect of high concentrations of phosphate on the production of a variety of secondary metabolites (reviewed in reference 27). However, most of these reports are basic accounts of the overall phosphate effect on the control of antibiotic production and were made before the gene clusters encoding the biosynthesis of secondary metabolites were sequenced. These early studies were helpful in designing medium composition to avoid phosphate control, thereby favoring the production of secondary metabolites that are expressed at very low levels.

PHOSPHATE CONTROL OF ANTIBIOTIC BIOSYNTHESIS AT THE TRANSCRIPTIONAL LEVEL
The phosphate control signals of antibiotic biosynthesis, i.e.,
the biochemical intermediates involved in the signal transduction
cascade, have long remained largely unknown. These signals appear
to be integrated with the inputs produced by other sensors of
environmental or nutritional stress, e.g., carbon or nitrogen
limitation (
7). Phosphate control of the biosynthesis of secondary
metabolites is exerted at the transcriptional and posttranscriptional
(antibiotic synthases activity) levels (reviewed in references
23 and
30). In at least two cases, it is clearly established
that phosphate control of the biosynthesis of the secondary
metabolites candicidin and oxytetracycline is exerted at the
transcriptional level (
3,
34). Expression of the
pabS gene of
S. griseus, which encodes the candicidin precursor-forming enzyme
p-aminobenzoic acid (PABA) synthase (
3), and expression of the
tetracycline biosynthesis genes
otcC,
otcX, and
otcY (
34) are
observed only under phosphate-limiting conditions.
otcC encodes
anhydrotetracycline oxygenase, and
otcY codes for the tetracycline
polyketide synthase, whereas
otcX is a gene divergent to
otcC encoding a protein of unknown function (
19).
The more advanced studies on phosphate control of secondary metabolites have been done with the model actinomycetes S. coelicolor and S. lividans (11, 16). The synthesis of the S. coelicolor pigmented secondary metabolites actinorhodin and undecylprodigiosin is also negatively controlled by high phosphate concentrations (11, 16). Actinorhodin is synthesized by a type II polyketide synthetase, whereas undecylprodigiosin is a pyrrolic compound derived from proline. Surprisingly, no transcriptional studies were available until recently (see below) on the molecular mechanism of phosphate control of the expression of the actinorhodin and undecylprodigiosin genes.
Genes encoding secondary metabolites are frequently linked in clusters (5, 29). Phosphate control appears to repress the expression of entire clusters of antibiotic biosynthesis genes, e.g., genes encoding the activating enzyme PABA-coenzyme A ligase and a thioesterase, in addition to PABA synthase in the candicidin gene cluster (6, 9) or the complete pimaricin gene cluster (2). A question that remains unanswered is whether each promoter corresponding to phosphate-sensitive genes contains a phosphate box or whether there is a master gene encoding a regulatory protein involved in the activation of antibiotic biosynthetic genes that in turn is controlled by the inorganic phosphate level.

ARE THERE PHO BOXES IN PHOSPHATE-REGULATED GENES IN STREPTOMYCES SPECIES?
In
E. coli and
B. subtilis, about 30 genes belonging to the
pho regulon are controlled by the two-component PhoR-PhoB (named
PhoR-PhoP in
B. subtilis) system (
18,
46). More genes of the
pho regulon have been identified by proteomics and transcriptional
studies of
B. subtilis (
1) and by microarray analysis of
Corynebacterium glutamicum (
21).
In E. coli, the sensor protein kinase PhoR self-phosphorylates under conditions of phosphate starvation (forming PhoR
P) that transfers its phosphate group to the dephosphorylated PhoB. The phosphorylated PhoB activates expression of about 30 phosphate-regulated genes by binding to the PHO boxes located in the 5' region of these genes (46). Expression of phoA and other members of the phosphate regulon takes place under phosphate-limiting conditions when the PhoB transcriptional activator is available in its phosphorylated form (PhoB
P). The mechanism is essentially identical in B. subtilis (18, 40). PHO boxes in E. coli consist of 18 nucleotides (C/T)TGTCATA(A/T)A(A/T)CTGTCA(T/C) formed by two direct repeats of 7 nucleotides (C/T)TGTCAT separated by four adenines or thymines. This sequence has been found, with minor changes, in the promoters of a variety of phosphate-controlled genes in different proteobacteria (30, 46) (Fig. 1).
Similar PHO boxes, although with a different consensus sequence,
occur in
B. subtilis. Each box consists of two hexanucleotides
[TT(A/T)ACA] repeated in tandem and separated by three to seven
nucleotides (
24), in contrast to
E. coli, for which the separation
of the two repeats in each PHO box is always of four nucleotides
(Fig.
1).
The full genome sequence of S. coelicolor (4) and S. avermitilis (20, 39) is now available, and some others will soon be accessible. Several research groups have provided evidence showing that the production of methylenomycin, actinorhodin, and undecylprodigiosin in cultures of S. coelicolor is reduced by high phosphate concentrations (11, 16). Until a few years ago, it was unclear whether standard PHO boxes might occur in the upstream regions of antibiotic biosynthesis genes (23). However, repeated searches to find standard PHO boxes in the upstream region of act (for actinorhodin) or red (for undecylprodigiosin) genes have been unsuccessful. Similarly, no consensus PHO boxes have been found in the upstream region of the phosphate-regulated ppk gene of S. lividans (8).
Expression of the act and red genes is regulated by the specific transcriptional activators ActII-ORF4 (12, 14) and RedD (37, 44). Similarly, expression of the daunorubicin gene cluster in Streptomyces peucetius is controlled by the transcriptional activator DnrI (45). The activator proteins ActII-ORF4, RedD, DnrI, and other pathway-specific regulators, such as CcaR in Streptomyces clavuligerus (41), belong to the group of SARP (Streptomyces antibiotic regulatory protein) regulators (50) that form part of the OmpR superfamily (31, 35, 41). It is possible that the expression of the transcriptional activators ActII-ORF4 and RedD is controlled by phosphate, but again, the upstream regions of these genes lack classical PHO boxes. Initial evidence suggests, however, that the phosphate effect is mediated by a different sequence in the GC-rich promoters of Streptomyces species than in E. coli.

THE STREPTOMYCES PhoR-PhoP SYSTEM IS INVOLVED IN PHOSPHATE CONTROL OF ACTINORHODIN AND UNDECYLPRODIGIOSIN
After the cloning and characterization of the extracellular
alkaline phosphatase (
phoA) gene of
S. griseus (
36), we found
three putative phosphatase genes in the
S. coelicolor genome.
One of them,
phoA (the putative extracellular alkaline phosphatase
gene) showed 71% identity to
S. griseus phoA, identified unequivocally
by sequencing of the amino-terminal end of the purified extracellular
alkaline phosphatase (
36). The biochemical characteristics of
PhoB are unknown and PhoC corresponds to a phosphodiesterase.
Recently, the phoR-phoP systems of S. coelicolor and S. lividans were cloned, and their role in actinorhodin and undecylprodigiosin biosynthesis in S. lividans was studied by gene disruption and gene replacement (43). The phoR-phoP cluster has also been identified and disrupted in the S. avermitilis genome (H. Ikeda, J. F. Martín, and S. Omura, unpublished data). In Streptomyces species, PhoR shows all of the characteristics of a transmembrane sensor protein, whereas PhoP is a member of the DNA-binding OmpR family (35). PhoR (426 amino acids; 45.4 kDa in S. coelicolor) has two hydrophobic, membrane-spanning regions in the N-terminal domain and a large extramembrane domain that may serve as a sensor of environmental signals (35, 43). In B. subtilis the cytoplasmic kinase domain of PhoR is sufficient for the low phosphate expression of the pho regulon genes (42). The S. coelicolor and S. lividans 24.7-kDa PhoP protein belonging to the OmpR family contains a DNA-binding domain in the carboxyl-terminal region (residues 190 to 201) (43).
The S. lividans phoR-phoP deletion mutants (named
phoP and
phoRP) lacking either PhoP or both PhoR and PhoP proteins are unable to synthesize extracellular alkaline phosphatase, as shown by Western blot analysis. The formation of alkaline phosphatase was restored by complementation of the deletion mutants with phoR-phoP, confirming the involvement (positive effect) of the two-component system in the phosphate control of phoA in this actinomycete (43). A very interesting finding is the observation that mutants with phoR-phoP deletions overproduce large amounts of actinorhodin and undecylprodigiosin in a manner that is partially insensitive to phosphate (1 to 10 mM) control.
Phosphate control of the biosynthesis of actinorhodin and undecylprodigiosin was restored by complementation of the
pho mutants with the phoR-phoP cluster (43). These results clearly indicate that expression of either primary metabolism genes such as phoA or genes involved in the biosynthesis of secondary metabolites such as actinorhodin and undecylprodigiosin are under the phosphate control mechanism mediated by PhoR-PhoP.

THE PhoR-PhoP ACTION ON ACTINORHODIN AND UNDECYLPRODIGIOSIN MAY BE MEDIATED BY THE PATHWAY-SPECIFIC REGULATORS
It is possible that there is a phosphate control mechanism of
antibiotic gene expression different from that recognizing the
classical PHO box sequences. It is important to note that, whereas
PhoP exerts a positive regulation on expression of the
phoA gene, as occurs in other bacteria, expression of
S. lividans or
S. coelicolor pigments and antibiotics is regulated negatively,
i.e., inactivation of the response regulator PhoP or deletion
of the entire PhoR-PhoP system results in overexpression of
actinorhodin and undecylprodigiosin. This suggests that the
modes of regulation of the alkaline phosphatase and secondary
metabolite genes are different and that the PhoR-PhoP action
on antibiotic gene expression may be mediated through other
DNA-binding proteins, e.g., pathway-specific regulators.
In S. lividans and S. coelicolor, there is a small (63-amino-acid) protein, AfsS, encoded by a short ORF located in the 3' region immediately downstream of the regulatory gene AfsR. AfsS is a rare protein (thus far, it is found only in a few Streptomyces species) that contains three repeats of the 11-amino-acid sequence TXXDHMPXXPA (where X represents any amino acid) (33). Overexpression of AfsS in S. lividans (or S. coelicolor) leads to an overproduction of actinorhodin and undecylprodigiosin, even in mutants disrupted in AfsR. Recently, Lee et al. (22) have shown that the afsS gene is the target for the AfsR regulator, a widespread transcription factor that has ATPase activity (47). S. lividans has an afsS analogue named afsR2 (49). Floriano and Bibb (13) reported that AfsS protein stimulates the production of actinorhodin by enhancing the transcription of the pathway-specific regulator ActII-ORF4 and that the same occurs in S. lividans when afsR2 was overexpressed.
A possible cascade mechanism involves a negative effect of phosphorylated PhoP on the expression of afsS, resulting in downregulation of actII-ORF4 and redD expression (Fig. 2). Due to their low concentration, ActII-ORF4 and RedD would be unable to induce the actinorhodin and undecylprodigiosin biosynthetic genes. Null phoR-phoP mutants lack the PhoP response regulator and therefore would be unable to repress the afs gene, leading to constitutive formation of AfsS, resulting in induction of actII-ORF4 and redD and finally in actinorhodin and undecylprodigiosin overproduction.

FUTURE PERSPECTIVES
The recent identification of a large number of structural and
regulatory genes involved in antibiotic biosynthesis permits
analysis of the mechanism of PhoR-PhoP-mediated global control
in other
Streptomyces species, some of which produce antibiotics,
antitumor agents, immunosuppressants, and many other biologically
active compounds of high commercial interest. In all of these
cases, phosphate represses the biosynthesis of these compounds,
and a proper understanding of the control mechanism in these
actinomycetes will allow targeted derepression of antibiotic
production.

ACKNOWLEDGMENTS
This work was supported by a grant from the Ministry of Education
and Science of Spain CICYT Bio2003 01489).
I thank P. Liras, A. Sola, and A. Rodriguez for valuable discussions.

FOOTNOTES
* Mailing address: Area of Microbiology, University of León, 24006, León, Spain. Phone: 34-987-291-506. Fax: 34-987-291-506. E-mail:
degjmm{at}unileon.es.


REFERENCES
1 - Antelmann, H., C. Scharf, and M. Hecker. 2000. Phosphate starvation-inducible proteins of Bacillus subtilis: proteomics and transcriptional analysis. J. Bacteriol. 182:4478-4490.[Abstract/Free Full Text]
2 - Aparicio, J. F., R. Fouces, M. V. Mendes, N. Olivera, and J. F. Martín. 2000. A complex multienzyme system encoded by five polyketide synthase genes is involved in the biosynthesis of the 26-membered polyene macrolide pimaricin in Streptomyces natalensis. Chem. Biol. 7:895-905.[CrossRef][Medline]
3 - Asturias, J. A., P. Liras, and J. F. Martín. 1990. Phosphate control of pabS gene transcription during candicidin biosynthesis. Gene 93:79-84.[CrossRef][Medline]
4 - Bentley, S. D., K. F. Chater, A. M. Cerdeño-Tarraga, G. L. Challis, N. R. Thomson, K. D. James, D. E. Harris, M. A. Quail, H. Kieser, D. Harper, A. Bateman, S. Brown, G. Chandra, C. W. Chen, M. Collins, A. Cronin, A. Fraser, A. Goble, J. Hidalgo, T. Hornsby, S. Howarth, C. H. Huang, T. Kieser, L. Larke, L. Murphy, K. Oliver, S. O'Neil, E. Rabbinowitsch, M. A. Rajandream, K. Rutherford, S. Rutter, K. Seeger, D. Saunders, S. Sharp, R. Squares, S. Squares, K. Taylor, T. Warren, A. Wietzorrek, J. Woodward, B. G. Barrell, J. Parkhill, and D. A. Hopwood. 2002. Complete genome sequence of the model actinomycete Streptomyces coelicolor A3(2). Nature 417:141-147.[CrossRef][Medline]
5 - Bibb, M. J. 1996. The regulation of antibiotic production in Streptomyces coelicolor A3(2). Microbiology 142:1335-1344.[Free Full Text]
6 - Campelo, A. B., and J. A. Gil. 2002. The candicidin gene cluster from Streptomyces griseus IMRU 3570. Microbiology 48:51-59.
7 - Chater, K. F., and M. J. Bibb. 1996. Regulation of bacterial antibiotic production, p. 59-105. In H. Kleinkauf and H. von Doren (ed.), Products of secondary metabolism. WCH, Weinheim, Germany.
8 - Chouayekh, H., and M. J. Virolle. 2002. The polyphosphate kinase plays a negative role in the control of antibiotic production in Streptomyces lividans. Mol. Microbiol. 43:919-930.[CrossRef][Medline]
9 - Criado, L. M., J. F. Martín, and J. A. Gil. 1993. The pabS gene of Streptomyces griseus, encoding p-aminobenzoic acid synthase, is located between genes possibly involved in candicidin biosynthesis. Gene 126:135-139.[CrossRef][Medline]
10 - Dekeva, M. L., J. A. Titus, and W. R. Strohl. 1985. Nutrient effects on anthracycline production by Streptomyces peucetius in a defined medium. Can. J. Microbiol. 31:287-294.[Medline]
11 - Doull, J. L., and L. C. Vining. 1990. Nutritional control of actinorhodin production by Streptomyces coelicolor A3(2): suppressive effects of nitrogen and phosphate. Appl. Microbiol. Biotechnol. 32:449-454.[CrossRef][Medline]
12 - Fernández-Moreno, M. A., J. L. Caballero, D. A. Hopwood, and F. Malpartida. 1991. The act cluster contains regulatory and antibiotic export genes, direct targets for translational control by the bldA transfer RNA gene of Streptomyces. Cell 66:769-780.[CrossRef][Medline]
13 - Floriano, B., and M. Bibb. 1996. afsR is a pleiotropic but conditionally required regulatory gene for antibiotic production in Streptomyces coelicolor A3(2). Mol. Microbiol. 21:385-396.[CrossRef][Medline]
14 - Gramajo, H. C., E. Takano, and M. J. Bibb. 1993. Stationary-phase production of the antibiotic actinorhodin in Streptomyces coelicolor A3(2) is transcriptionally regulated. Mol. Microbiol. 7:837-845.[CrossRef][Medline]
15 - Hobbs, G., C. M. Frazer, D. C. J. Gardner, F. Flett, and S. G. Oliver. 1990. Pigmented antibiotic production by Streptomyces coelicolor A3(2): kinetics and the influence of nutrients. J. Gen. Microbiol. 136:2291-2296.
16 - Hobbs, G., A. I. C. Obanye, J. Petty, J. C. Mason, E. Barrat, D. C. J. Gardner, F. Flett, C. P. Smith, P. Broda, and S. G. Oliver. 1992. An integrated approach to studying regulation of production of the antibiotic methylenomycin by Streptomyces coelicolor A3(2). J. Bacteriol. 174:1487-1494.[Abstract/Free Full Text]
17 - Horinouchi, S., and T. Beppu. 1992. Autoregulatory factors and communication in actinomycetes. Annu. Rev. Microbiol. 46:377-398.[CrossRef][Medline]
18 - Hulett, F. M. 1996. The signal transduction network for Pho regulation. Mol. Microbiol. 19:933-939.[CrossRef][Medline]
19 - Hunter, I. S., and R. A. Hill. 1997. Tetracyclines: chemistry and molecular genetics of their formation, p. 659-682. In W. Strohl (ed.), Biotechnology of industrial antibiotics. Marcel Decker, Inc., New York, N.Y.
20 - Ikeda, H., J. Ishikawa, A. Hanamoto, M. Shinose, H. Kikuchi, T. Shiba, Y. Sakaki, M. Hattori, and S. Omura. 2003. Complete genome sequence and comparative analysis of the industrial microorganism Streptomyces avermitilis. Nat. Biotechnol. 21:526-531.[CrossRef][Medline]
21 - Ishige, T., M. Krause, M. Bott, V. F. Wendisch, and H. Sahm. 2003. The phosphate starvation stimulon of Corynebacterium glutamicum determined by DNA microarray analyses. J. Bacteriol. 185:4519-4529.[Abstract/Free Full Text]
22 - Lee, P.-C., T. Umeyama, and S. Horinouchi. 2002. afsS is a target of AfsR, a transcriptional factor with ATPase activity that globally controls secondary metabolism in Streptomyces coelicolor A3(2). Mol. Microbiol. 43:1413-1430.[CrossRef][Medline]
23 - Liras, P., J. A. Asturias, and J. F. Martín. 1990. Phosphate control sequences involved in transcriptional regulation of antibiotic biosynthesis. Trends Biotechnol. 8:184-189.[CrossRef][Medline]
24 - Liu, W., and F. M. Hulett. 1998. Comparison of PhoP binding to the tuaA promoter with PhoP binding to other Pho-regulon promoters establishes a Bacillus subtilis Pho core binding site. Microbiology 144:1443-1450.[Abstract/Free Full Text]
25 - Lounes, A., A. Lebrihi, C. Benslimane, G. Lefebvre, and P. Germain. 1996. Regulation of spiramycin synthesis in Streptomyces ambofaciens: effects of glucose and inorganic phosphate. Appl. Microbiol. Biotechnol. 45:204-211.[CrossRef][Medline]
26 - Mapplestone, R. A., M. J. Stone, and D. H. Williams. 1992. The evolutionary role of secondary metabolites: a review. Gene 115:151-157.[CrossRef][Medline]
27 - Martín, J. F. 1989. Molecular mechanism for the control by phosphate of the biosynthesis of antibiotic and secondary metabolites, p. 213-237. In S. Shapiro (ed.), Regulation of secondary metabolism in actinomycetes. CRC Press, Inc., Boca Raton, Fla.
28 - Martín, J. F., and A. Demain. 1980. Control of antibiotic biosynthesis. Microbiol. Rev. 44:230-251.[Free Full Text]
29 - Martín, J. F., and P. Liras. 1989. Organization and expression of genes involved in the biosynthesis of antibiotics and other secondary metabolites. Annu. Rev. Microbiol. 43:173-206.[Medline]
30 - Martín, J. F., A. T. Marcos, A. Martín, J. A. Asturias, and P. Liras. 1994. Phosphate control of antibiotic biosynthesis at the transcriptional level, p. 140-147. In A. Torriani-Gorini, E. Yagil, and S. Silver (ed.), Phosphate in microoganisms. ASM Press, Washington, D.C.
31 - Martínez-Hackert, E., and A. M. Stock. 1997. Structural relationships in the OmpR family of winged-helix transcription factors. J. Mol. Biol. 269:301-312.[CrossRef][Medline]
32 - Masuma, R., Y. Tanaka, H. Tanaka, and S. Omura. 1986. Production of nanomycin and other antibiotics by phosphate-depressed fermentation using phosphate-trapping agents. J. Antibiot. 39:1557-1564.[Medline]
33 - Matsumoto, A., H. Ishizuka, T. Beppu, and S. Horinouchi. 1995. Involvement of a small ORF downstream of the afsR gene in the regulation of secondary metabolism in Streptomyces coelicolor A3(2). Actinomycetologica 9:37-43.
34 - McDowall, K., A. Thamchaipenet, and I. S. Hunter. 1999. Phosphate control of oxytetracycline production by Streptomyces rimosus is at the level of transcription from promoters overlapped by tandem repeats similar to those of the DNA-binding sites of the OmpR family. J. Bacteriol. 181:3025-3032.[Abstract/Free Full Text]
35 - Mizuno, T., and I. Tanaka. 1997. Structure of the DNA-binding domain of the OmpR family of response regulators. Mol. Microbiol. 24:665-667.[CrossRef][Medline]
36 - Moura, R. S., J. F. Martín, A. Martín, and P. Liras. 2001. Substrate analysis and molecular cloning of the extracellular alkaline phosphatase of Streptomyces griseus. Microbiology 147:1525-1533.[Abstract/Free Full Text]
37 - Narva, K. E., and J. S. Feitelson. 1990. Nucleotide sequence and transcriptional analysis of the redD locus of Streptomyces coelicolor A3(2). J. Bacteriol. 172:326-333.[Abstract/Free Full Text]
38 - Nodwell, J. R., and R. Losick. 1998. Purification of an extracellular signaling molecule involved in production of the aerial mycelium by Streptomyces coelicolor. J. Bacteriol. 180:1334-1337.[Abstract/Free Full Text]
39 - Omura, S., H. Ikeda, J. Ishikawa, A. Hanamoto, C. Takahashi, M. Shinose, Y. Takahashi, H. Horikawa, H. Nakazawa, T. Osonoe, H. Kikuchi, T. Shiba, Y. Sakaki, and M. Hattori. 2001. Genome sequence of an industrial microorganism Streptomyces avermitilis: deducing the ability of producing secondary metabolites. Proc. Natl. Acad. Sci. USA 98:12215-12220.[Abstract/Free Full Text]
40 - Pragai, Z., and C. R. Harwood. 2002. Regulatory interactions between the Pho and
B-dependent general stress regulons of Bacillus subtilis. Microbiology 148:1593-1602.[Abstract/Free Full Text]
41 - Santamarta, I., A. Rodríguez-García, R. Pérez-Redondo, J. F. Martín, and P. Liras. 2002. CcaR is an autoregulatory protein that binds to the ccaR and cefD-cmcI promoters of the cephamycin C-clavulanic acid cluster in Streptomyces clavuligerus. J. Bacteriol. 184:3106-3113.[Abstract/Free Full Text]
42 - Shi, L., and F. M. Hulett. 1999. The cytoplasmic kinase domain of PhoR is sufficient for the low phosphate-inducible expression of pho regulon genes in Bacillus subtilis. Mol. Microbiol. 31:211-222.[CrossRef][Medline]
43 - Sola-Landa, A., R. S. Moura, and J. F. Martín. 2003. The two-component PhoR-PhoP system controls both primary metabolism and secondary metabolite biosynthesis in Streptomyces lividans. Proc. Natl. Acad. Sci. USA 100:6133-6138.[Abstract/Free Full Text]
44 - Takano, E., H. C. Gramajo, E. Strauch, N. Andres, J. White, and M. J. Bibb. 1992. Transcriptional regulation of the redD transcriptional activator gene accounts for growth-phase-dependent production of the antibiotic undecylprodigiosin in Streptomyces coelicolor A3(2). Mol. Microbiol. 6:2797-2804.[CrossRef][Medline]
45 - Tang, L., A. Grimm, Y. X. Zhang, and C. R. Hutchinson. 1996. Purification and characterization of the DNA-binding protein DnrI, a transcriptional factor of daunorubicin biosynthesis in Streptomyces peucetius. Mol. Microbiol. 22:801-813.[CrossRef][Medline]
46 - Torriani-Gorini, A. 1994. The Pho regulon of Escherichia coli, p. 1-4. In A. Torriani-Gorini, E. Yagil, and S. Silver (ed.), Phosphate in microorganisms. ASM Press, Washington, D.C.
47 - Umeyama, T., P.-C. Lee, and S. Horinouchi. 2002. Protein serine/threonine kinases in signal transduction for secondary metabolism and morphogenesis in Streptomyces. Appl. Microbiol. Biotechnol. 59:419-425.[CrossRef][Medline]
48 - Vining, L. C. 1992. Secondary metabolism, inventive evolution and biochemical diversity: a review. Gene 115:135-140.[CrossRef][Medline]
49 - Vögtli, M., P. C. Chang, and S. N. Cohen. 1994. afsR2: a previously undetected gene encoding a 63-amino-acid protein that stimulates antibiotic production in Streptomyces lividans. Mol. Microbiol. 14:643-653.[CrossRef][Medline]
50 - Wietzorrek, A., and M. J. Bibb. 1997. A novel family of proteins that regulates antibiotic production in Streptomyces appears to contain an OmpR-like DNA-binding fold. Mol. Microbiol. 25:1181-1184.[CrossRef][Medline]
51 - Yamada, Y., and T. Nihira. 1999. Microbial hormones and microbial chemical ecology, p. 377-413. In K. Mori (ed.), Comprehensive natural products chemistry, vol. 8. Elsevier Scientific Publishers, Dordrecht, The Netherlands.
Journal of Bacteriology, August 2004, p. 5197-5201, Vol. 186, No. 16
0021-9193/04/$08.00+0 DOI: 10.1128/JB.186.16.5197-5201.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.
This article has been cited by other articles:
-
Rodriguez-Garcia, A., Sola-Landa, A., Apel, K., Santos-Beneit, F., Martin, J. F.
(2009). Phosphate control over nitrogen metabolism in Streptomyces coelicolor: direct and indirect negative control of glnR, glnA, glnII and amtB expression by the response regulator PhoP. Nucleic Acids Res
37: 3230-3242
[Abstract]
[Full Text]
-
Sola-Landa, A., Rodriguez-Garcia, A., Apel, A. K., Martin, J. F.
(2008). Target genes and structure of the direct repeats in the DNA-binding sequences of the response regulator PhoP in Streptomyces coelicolor. Nucleic Acids Res
36: 1358-1368
[Abstract]
[Full Text]
-
Apel, A. K., Sola-Landa, A., Rodriguez-Garcia, A., Martin, J. F.
(2007). Phosphate control of phoA, phoC and phoD gene expression in Streptomyces coelicolor reveals significant differences in binding of PhoP to their promoter regions. Microbiology
153: 3527-3537
[Abstract]
[Full Text]
-
Anton, N., Santos-Aberturas, J., Mendes, M. V., Guerra, S. M., Martin, J. F., Aparicio, J. F.
(2007). PimM, a PAS domain positive regulator of pimaricin biosynthesis in Streptomyces natalensis. Microbiology
153: 3174-3183
[Abstract]
[Full Text]
-
Philippe, V. A., Mendez, M. B., Huang, I-H., Orsaria, L. M., Sarker, M. R., Grau, R. R.
(2006). Inorganic Phosphate Induces Spore Morphogenesis and Enterotoxin Production in the Intestinal Pathogen Clostridium perfringens.. Infect. Immun.
74: 3651-3656
[Abstract]
[Full Text]
-
Asensio, J. G., Maia, C., Ferrer, N. L., Barilone, N., Laval, F., Soto, C. Y., Winter, N., Daffe, M., Gicquel, B., Martin, C., Jackson, M.
(2006). The Virulence-associated Two-component PhoP-PhoR System Controls the Biosynthesis of Polyketide-derived Lipids in Mycobacterium tuberculosis. J. Biol. Chem.
281: 1313-1316
[Abstract]
[Full Text]
-
Ghorbel, S., Kormanec, J., Artus, A., Virolle, M.-J.
(2006). Transcriptional Studies and Regulatory Interactions between the phoR-phoP Operon and the phoU, mtpA, and ppk Genes of Streptomyces lividans TK24. J. Bacteriol.
188: 677-686
[Abstract]
[Full Text]