The unusual substrate specificity of Escherichia coli cardiolipin synthase C does not require the product of the transcriptionally engaged ymdB gene

Abstract

- ClsC drives cardiolipin (CL) synthesis even when YmdB is not transcriptionally paired.Polycistronic transcription and translation of ymdB-clsC which has been thought to be required for full activity of ClsC is not necessary for CL synthesis or the substrate specificity of ClsC, which condenses phosphatidylethanolamine (PE) and phosphatidylglycerol (PG).The authentic initiation codon of the clsC gene is present within the open reading frame of the upstream located ymdB gene.- Initiation of translation from this newly identified authentic initiation codon is essential for ClsC to exert its cardiolipin synthase activity both in vivo and in vitro.