Functional analysis of the secretory precursor processing machinery of Bacillus subtilis: identification of a eubacterial homolog of archaeal and eukaryotic signal peptidases.

ABSTRACT: Approximately 47% of the genes of the Gram-positive bacterium Bacillus subtilis belong to paralogous gene families. The present studies were aimed at the functional analysis of the sip gene family of B. subtilis, consisting of five chromosomal genes, denoted sipS, sipT, sipU, sipV, and sipW. All five sip genes specify type I signal peptidases (SPases), which are actively involved in the processing of secretory preproteins. Interestingly, strains lacking as many as four of these SPases could be obtained. As shown with a temperature-sensitive SipS variant, only cells lacking both SipS and SipT were not viable, which may be caused by jamming of the secretion machinery with secretory preproteins. Thus, SipS and SipT are of major importance for protein secretion. This conclusion is underscored

SUBMITTER: Tjalsma H 

PROVIDER: S-EPMC317044 | biostudies-literature | 1998 Aug

REPOSITORIES: biostudies-literature