PROSITE documentation PDOC00093
Chloramphenicol acetyltransferase active site


Chloramphenicol O-acetyltransferase (CAT) (EC [1] catalyzes the acetyl-CoA dependent acetylation of chloramphenicol (Cm), an antibiotic which inhibits prokaryotic peptidyltransferase activity. Acetylation of Cm by CAT inactivates the antibiotic. A histidine residue, located in the C-terminal section of the enzyme, plays a central role in its catalytic mechanism. We derived a signature pattern from the region surrounding this active site residue.


There is a second family of CAT [2], evolutionary unrelated to the main family described above. These CAT belong to the bacterial hexapeptide-repeat containing-transferases family (see <PDOC00094>).

Last update:

November 1997 / Text revised.


Technical section

PROSITE method (with tools and information) covered by this documentation:

CAT, PS00100; Chloramphenicol acetyltransferase active site  (PATTERN)


1AuthorsShaw W.V. Leslie A.G.W.
TitleChloramphenicol acetyltransferase.
SourceAnnu. Rev. Biophys. Biophys. Chem. 20:363-386(1991).
PubMed ID1867721

2AuthorsParent R. Roy P.H.
TitleThe chloramphenicol acetyltransferase gene of Tn2424: a new breed of cat.
SourceJ. Bacteriol. 174:2891-2897(1992).
PubMed ID1314803

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