Previous Article | Next Article ![]()
Journal of Bacteriology, March 2000, p. 1286-1295, Vol. 182, No. 5
Departments of Molecular
Microbiology1 and Cell
Biology,2 John Innes Centre, Colney, Norwich
NR4 7UH, United Kingdom
Received 4 October 1999/Accepted 5 December 1999
The whiD locus, which is required for the
differentiation of Streptomyces coelicolor aerial hyphae
into mature spore chains, was localized by map-based cloning to the
overlap between cosmids 6G4 and D63 of the minimal ordered library of
Redenbach et al. (M. Redenbach et al., Mol. Microbiol. 21:77-96,
1996). Subcloning and sequencing showed that whiD encodes a
homologue of WhiB, a protein required for the initiation of sporulation
septation in S. coelicolor. WhiD and WhiB belong to a
growing family of small (76- to 112-residue) proteins of unknown
biochemical function in which four cysteines are absolutely conserved;
all known members of this family are found in the actinomycetes. A
constructed whiD null mutant showed reduced levels of
sporulation, and those spores that did form were heat sensitive, lysed
extensively, and were highly irregular in size, arising at least in
part from irregularity in septum placement. The whiD null
mutant showed extreme variation in spore cell wall deposition; most
spores had uniformly thin (20- to 30-nm) walls, but spore chains were
frequently observed in which there was irregular but very pronounced
(up to 170 nm) cell wall thickening at the junctions between spores.
whiD null mutant spores were frequently partitioned into
irregular smaller units through the deposition of additional septa,
which were often laid down in several different planes, very close to
the spore poles. These "minicompartments" appeared to be devoid of
chromosomal DNA. Two whiD promoters, whiDp1 and
whiDp2, were identified, and their activities were analyzed
during development of wild-type S. coelicolor on solid
medium. Both promoters were developmentally regulated;
whiDp1 and whiDp2 transcripts were detected
transiently, approximately at the time when sporulation septa were
observed in the aerial hyphae.
0021-9193/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.
WhiD and WhiB, Homologous Proteins Required for
Different Stages of Sporulation in Streptomyces
coelicolor A3(2)
*
Corresponding author. Mailing address: Department of
Molecular Microbiology, John Innes Centre, Colney, Norwich NR4 7UH,
United Kingdom. Phone: (44) 1603-452571. Fax: (44) 1603-456844. E-mail: virginie.molle{at}bbsrc.ac.uk.
This article has been cited by other articles:
| Appl. Environ. Microbiol. | Infect. Immun. | Eukaryot. Cell |
|---|---|---|
| Mol. Cell. Biol. | J. Virol. | Microbiol. Mol. Biol. Rev. |
| ALL ASM JOURNALS |