Bm. Corfe et al., THE GERB REGION OF THE BACILLUS-SUBTILIS-168 CHROMOSOME ENCODES A HOMOLOG OF THE GERA SPORE GERMINATION OPERON, Microbiology, 140, 1994, pp. 471-478
Spores of gerB spore germination mutants of Bacillus subtilis 168 are
defective in response to the germinative mixture of L-asparagine, gluc
ose. fructose and potassium ions (AGFK), but are normal in the L-alani
ne (ALA) triggered germination response. A lambda clone of 15 kbp carr
ying the gerB region has been identified. Sequencing of the gerB regio
n of the clone revealed a cluster of three ORFs encoding putative prot
eins of 53.3, 41.3 and 42.4 kDa (GerBA, GerBB and GerBC, respectively)
. The first two of these proteins have substantial hydrophobic regions
and the third is a possible lipoprotein. At least two, and probably a
ll three products are required for normal germination in AGFK. The thr
ee proteins form a set of homologues of the products of the gerA opero
n, mutations in which cause a defect in the ALA germination pathway, b
ut cause no defect in AGFK. The GerB proteins show 42%, 31% and 35% id
entity at the amino-acid level to the corresponding GerA proteins, and
the homologues occur in the same order in both operons.