Part of a cryptic operon that encodes proteins involved in type II secretion pathway in other organisms, but is not expressed in strain K12 under standard laboratory conditions (PubMed:8655552). May play a regulatory role under conditions of derepressed gsp gene expression (PubMed:11118204). Silenced by the DNA-binding protein H-NS under standard growth conditions. Was originally identified as the 11.3 kDa PinO protein, a calcium-binding protein synthesized in the absence of isoleucine in relA stains, which may be required for the initiation of chromosome replication (PubMed:1925011, PubMed:1938934). But GspB is predicted to be 15.9 kDa and has isoleucine residues, and there is no evidence that gspB encodes the PinO peptide or that it binds calcium.