Altered Arrangement of Proteins in the Spore Coat of a Germination Mutant of Bacillus subtilis

Abstract

Spores produced by a B. subtilis mutant were slow to develop their resistance properties during sporulation and were slower to germinate than were wild-type spores. The coat protein composition of the mutant spores, as analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, was similar to that of the wild-type spores. A protein (MW 12,000) which is normally present in the outermost layers of mature wild-type spores and which is surface-exposed was assembled abnormally into the coat of the mutant spores and not surface-exposed. The mutation responsible for this phenotype (spo-520) was mapped between pheA and leuB on the B. subtilis chromosome and was 47% cotransformable with leuB16. This mutation, and 3 others closely linked to it, define a new sporulation locus, spoVIB, which is involved in spore coat assembly. The phenotype of the mutant(s) supports the contention that spore germination and resistance properties may be determined by the assembly of the coat.