CPS operon

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The capsule biosynthesis, or CPS operon, is a section of the genome present in some Escherichia coli, of which regulates the production of polysaccharides making up the bacterial capsule.[1] These polysaccharides help protect the bacteria from harsh environments, toxic chemicals, and bacteriophages.

The CPS operon contains genes which code for the following proteins:

The CPS operon is likely transcriptionally regulated by the Rcs (regulation of capsule synthesis) proteins.[1] Reduced levels of membrane-derived oligosaccharides result in autophosphorylation of RcsC. This results in a phosphate group being transferred from RcsC to RcsB. RcsB then binds to RcsA, forming a complex which acts on the CPS promoter and activates transcription of the CPS genes.

The same operon is present in Klebsiella species, possibly as a result of horizontal gene transfer.[1]

References

  1. ^ a b c d e f g h Whitfield C (2006). "Biosynthesis and assembly of capsular polysaccharides in Escherichia coli". Annual Review of Biochemistry. 75: 39–68. doi:10.1146/annurev.biochem.75.103004.142545. PMID 16756484.