9.A.13 The Colicin J Lysis (Cjl) Family

The colicin J lysis peptide Cjl is 65 aas long. There are several homologues in the databases. It is encoded within an operon in Shigella sonnei which includes the cgl(ORF65) and cga(ORF94; colicin J) genes. No transmembrane helix (TMpred), no signal peptide, and no prokaryotic protein motif (PROSITE) was identified in Cjl. Cjl has been shown to promote selective colicin J release from producer bacteria (Smajs and Weinstock, 2001). It may do so initially by forming pores before inducing cell lysis. The cjl gene superficially resembles the kil genes of some colicin plasmids coding for semispecific release of colicins from the producer bacteria. Expression of the kil genes also results in cell lysis and is regulated by the promoter that controls colicin gene expression.

The presumed transport reaction catalyzed by the colicin J lysis (Cjl) protein is:

colicin J (in) Æ colicin J (out)