The Ger Receptor Family

Ger receptor activation is the first committed step in the germination process. Ger receptors are encoded, in general, as tricistronic operons containing three protein-coding genes, the A-, B-, and C-subunits. However, some Ger receptor subunits are encoded as orphan monocistronic genes and yet other ger receptor operons encode duplicated subunit genes.

The A-subunit protein of Ger receptors consist of five or six predicted membrane-spanning domains, as well as large N- and C-terminal hydrophilic domains. A-subunit proteins share significant homology to SpoVAF, a late-sporulation protein with no known function. Intriguingly, Ger receptors have been shown to interact with proteins from the spoVA operon. Whether these interactions are relevant to spore germination remains to be elucidated.

Further reading: The Ger Receptor Family from Sporulating Bacteria