The yabG gene of Bacillus subtilis encodes a sporulation specific proteasewhich is involved in the processing of several spore coat proteins

The synthesis and proteolysis of the spore coat proteins, SpoIVA and YrbA, of Bacillus subtilis were analyzed using antisera. Almost no intact full-le ngth proteins of either type were extracted from wild-type spores, while ya bG mutant spores contained intact SpoIVA and YrbA proteins. We purified rec ombinant YrbA and YabG proteins from Escherichia coli transformants and fou nd that YrbA was cleaved to the smaller moiety in the presence of YabG in v itro. These observations indicate that YabG is a protease involved in the p roteolysis and maturation of SpoIVA and YrbA proteins, conserved with the c ortex and/or coat assembly by B. subtilis. (C) 2000 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights re served.