Growth phase-dependent regulation and membrane localization of SpaB, a protein involved in biosynthesis of the lantibiotic subtilin

Abstract

The information responsible for biosynthesis of the lantibiotic subtilin is organized in an operon-like structure that starts with the spaB gene. The spaB gene encodes an open reading frame consisting of 1,030 amino acid residues, and it was calculated that a protein having a theoretical molecular mass of 120.5 kDa could be produced from this gene. This is consistent with the apparent molecular weight for SpaB of 115,000 which was estimated after sodium dodecyl sulfate-gel electrophoresis and identification with SpaB-specific antibodies. The SpaB protein is very similar to proteins EpiB and NisB, which were identified previously as being involved in epidermin and nisin biosynthesis. Upstream from SpaB a characteristic sigma A promotor sequence was identified. An immunoblot analysis revealed that SpaB expression was strongly regulated. No SpaB protein was detected in the early logarithmic growth phase, and maximum SpaB expression was observed in the early stationary growth phase. The expression of SpaB was strongly correlated with subtilin biosynthesis. Deletion mutations in either of two recently identified regulatory genes, spaR and spaK, which act as a "twocomponent" regulatory system necessary for growth phase-dependent induction of subtilin biosynthesis (C. Klein, C. Kaletta, and K. D. Entian, Appl. Environ. Microbiol. 59:296-303, 1993), also resulted in failure of SpaB expression. To investigate the intracellular localization of SpaB, vesicles of BaciUus subtilis were prepared. The SpaB protein cosedimented with the vesicle fraction and was released only after vigorous resuspension of the vesicles. Our results suggest that SpaB is membrane associated and that subtilin biosynthesis occurs at the cytoplasmic membrane of B. subtilis.

Antimicrobial activity of Bacillus subtilis and Bacillus pumilus during the fermentation of African locust bean (Parkia biglobosa) for Soumbala production

“…that the indicator microorganisms might have variable sensitivity regarding the antimicrobial substances or are inactivated by different compounds produced at different time of the Bacillus isolates growth. In fact, Bacillus isolates produce different antimicrobial compounds during the logarithmic and/or stationary growth phase as well as in sporulated form (Klein et al 1993;Gutowski-Eckel et al 1994;Stöver and Driks 1999). The production of Soumbala and most of the fermented foods in Africa depend on uncontrolled fermentation with sometimes inherent hygienic, nutritional and organoleptic defects.…”

Quorum sensing by peptide pheromones and two‐component signal‐transduction systems in Gram‐positive bacteria

“…Production of the lantibiotic nisin by Lactococcus lactis and subtilin by B. subtilis starts at early-to mid-logarithmic growth phase and increases to a maximal production level in the early stationary phase (Gutowski-Eckel et al, 1994;de Ruyter et al, 1996b). Interestingly, the nisin and the subtilin biosynthetic gene clusters (Fig.…”

Localization and Interaction of the Biosynthetic Proteins for the Lantibiotic, Nukacin ISK-1

“…This result clearly indicates the presence of NukM and NukT at the cytoplasm membrane and also suggests that nukacin ISK-1 maturation would occur at the cytoplasm membrane since it was found in type-A(I) lantibiotics. 20,26,27)…”