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. Author manuscript; available in PMC: 2009 Jul 1.
Published in final edited form as: Mol Microbiol. 2008 Jul;69(2):402–417. doi: 10.1111/j.1365-2958.2008.06289.x

Figure 2. Isolation of J suppressor mutants partially restored for spore formation and σG activation.

Figure 2

A. Spore formation is partially restored to J suppressor mutants a-e. Cells were induced to sporulate for 24 hours in DSM medium, and spores were measured as heat resistant colony forming units. With the exception of the parental wild-type strain (WT; PY79), all strains expressed PspoIIQ-sigG in place of endogenous sigG and were deleted for csfB. Cells harbored a wild-type copy of the J gene (J+; AHB480), lacked J (ΔJ; AHB434), or lacked J and harbored one of the five indicated suppressors (ΔJ suppressors a-e; AHB442, AHB547, AHB543, AHB438, AHB551, respectively). Error bars indicate standard deviation.

B. σG activation is partially restored to J mutant cells harboring suppressors a-e. σG–dependent PsspB-lacZ expression was monitored during sporulation of cells harboring a wild-type copy of the J gene (J+; AHB352), lacking J (ΔJ; AHB366), or lacking J and harboring one of the five indicated suppressors (ΔJ suppressors a-e; AHB419, AHB422, AHB420, AHB418, AHB423, respectively). All strains expressed PspoIIQ-sigG in place of endogenous sigG and were deleted for csfB. β-galactosidase activity was normalized to the maximal activity observed for the J+ wild type control strain (% WT maximum).

C. Cartoon of proteins encoded by J suppressor mutant genes yqjG, spoIIIAE, and pbpG. The predicted membrane topology of YqjG is based on that presented by Tjalsma et al. (2003). The N-terminal signal peptide and membrane topology of SpoIIIAE (referred to in the main text as AE) was predicted by the PolyPhobius algorithm (Kall et al., 2005, Kall et al., 2007). The SignalP algorithm (Bendtsen et al., 2004) indicated a high likelihood of signal peptidase (SP) cleavage at the site indicated. The membrane topology of PbpG is based on results from the PolyPhobius algorithm (Kall et al., 2005, Kall et al., 2007) and is consistent with the fact that high molecular weight PBPs are typically anchored in the cytoplasmic membrane by a non-cleavable N-terminal signal peptide (Ghuysen, 1994). Amino acid alterations isolated as J suppressors in each of the three proteins are indicated with asterisks.