Table 1

Substrate specificity of orthologous aaPGS enzymes, cellular aaPG content, and acidic induction

StrainEnzyme/ORFMethod(s) for specificity determination (reference)aSpecificity (reference)% aaPG of overall lipid content (reference)bAcidic inductionc
Bacillus anthracis strain SterneBAS1375ACTD, E (77)L-PG (77)10 (77)ND
Bacillus licheniformis ATCC 14580YfiXACTD, C, D, EL-PG3
Bacillus thuringiensis ATCC 10792Bthur0008_13400AFL, BFL, C, DL-PG10
Streptococcus thermophilus ATCC 19258stu1256ACTD, C, EL-PG10ND
Pseudomonas aeruginosa UCBPP-PA14PA14_52350CA-PG0.5/4+
Pseudomonas putida KT2440PP_1202CA-PG0.5/5+
Burkholderia phymatum STM 815Bphy_4019AFL, BFL, DA-PG0.5
Kineococcus radiotolerans SRS 30216Krad_4555AFL, BFL, DA-PG0.5
Paenibacillus polymyxa ATCC 842A-PGSAFL, BFL, C, DA-PG4
Methanosarcina barkeri ATCC 29787Mbar_A2435BFLA-PGNDND
  • a Methods for specificity determination using either recombinant full-length protein (FL) or C-terminal domain (CTD): A, lipid analysis by molybdatophosphoric acid staining of E. coli cells producing the recombinant protein; B, in vitro assay using 14C-amino acids. Specificity determination using native strains: C, lipid analysis by molybdatophosphoric acid staining; D, lipid analysis by ninhydrin staining; E, mass spectrometry of respective lipid spot.

  • b Cellular aaPG amounts have been determined from two-dimensional TLC analyses. Values are related to the overall lipid content. The potential induction of aaPG synthesis under acidic growth conditions was analyzed as described in Materials and Methods, and values for neutral conditions (pH 7.3)/acidic conditions (pH 5.3) are indicated. ND, not determined.

  • c ND, not determined; −, no increase of cellular aaPG concentrations; +, significantly elevated cellular aaPG concentrations under acidic growth conditions (see Fig. S2 and S3 in the supplemental material).