A gene encoding a small, acid-soluble spore protein from alkaliphilic Bacillus firmus OF4.

An 1100-bp DNA fragment cloned from alkaliphilic Bacillus firmus OF4 contained an open reading frame deduced to encode a 54-amino-acid, glutamine-rich protein with 35.6% identity to Bacillus subtilis small, acid-soluble spore protein-gamma (SASP-gamma) in a 45-aa overlap. This ORF, designated sspA, lacks the lengthy sequence repeat characteristic of previously cloned SASP-gamma-encoding genes. Southern analysis under conditions of moderate stringency revealed six bands, suggesting the presence of several related genes in the alkaliphile.