Binding Site

APOBEC/CMP deaminase, zinc-binding (IPR016192)

Short name: APOBEC/CMP_deaminase_Zn-bd


Cytidine deaminase (EC: (cytidine aminohydrolase) catalyzes the hydrolysis of cytidine into uridine and ammonia while deoxycytidylate deaminase (EC: (dCMP deaminase) hydrolyzes dCMP into dUMP. Both enzymes are known to bind zinc and to require it for their catalytic activity [PMID: 1567863, PMID: 8428902]. These two enzymes do not share any sequence similarity with the exception of a region that contains three conserved histidine and cysteine residues which are thought to be involved in the binding of the catalytic zinc ion.

Such a region is also found in other proteins [PMID: 8061614, PMID: 8203015]:

  • Yeast cytosine deaminase (EC: (gene FCY1) which transforms cytosine into uracil.
  • Mammalian apolipoprotein B mRNA editing protein, responsible for the postranscriptional editing of a CAA codon into a UAA (stop) codon in the APOB mRNA.
  • Riboflavin biosynthesis protein ribG, which converts 2,5-diamino-6-(ribosylamino)-4(3H)-pyrimidinone 5'-phosphate into 5-amino-6-(ribosylamino)-2,4(1H,3H)-pyrimidinedione 5'-phosphate.
  • Bacillus cereus blasticidin-S deaminase (EC:, which catalyzes the deamination of the cytosine moiety of the antibiotics blasticidin S, cytomycin and acetylblasticidin S.
  • Bacillus subtilis protein comEB. This protein is required for the binding and uptake of transforming DNA.
  • B. subtilis hypothetical protein yaaJ.
  • Escherichia coli hypothetical protein yfhC.
  • Yeast hypothetical protein YJL035c.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0016787 hydrolase activity
GO:0008270 zinc ion binding

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE patterns