184.108.40.206 - Cytidine deaminase
- Cytosine nucleoside deaminase.
- Cytidine aminohydrolase.
- (Deoxy)cytidine deaminase.
2'-deoxycytidine + H(+) + H2O = 2'-deoxyuridine + NH4(+)
The catalytic zinc ion is bound to His102, Cys129, Cys132, and a catalytic water. The positive charge of the metal ion polarises the O-H bond in water, increasing its acidity towards the close proximity Glu104. Thus, the first step involved the proton transfer from the zinc-bound water to Glu104, the rotation of the carboxyl group of Glu104 and the proton transfer from the protonated Glu104 to cytosine. The subsequent nucleophilic attack at the C2 of the substrate by the resulting hydroxide anion leads to a tetrahedral intermediate. The second step concerns the formation of both ammonia and uracil. Once again this steps involves the proton transfers from the zinc-bound hydroxide anion to Glu104 and from Glu104 to the amine group which are stepwise rather than synchronous as in the first step. This step forms ammonia and uracil. Uracil remains strongly bound to the zinc metal. The final step consists of several proton transfers shuttled by Glu104 and one nucleophilic attack. One water molecule, which replaces the ammonia from the second step, heterolytically splits with its proton going to Glu104 and the hydroxide anion synchronously attacking C2 of uracil.
|AA||Uniprot||Uniprot Resid||PDB||PDB Resid|
proton transfer, unimolecular elimination by the conjugate base, bimolecular nucleophilic addition, native state of enzyme regenerated, deamination
There are no kinetic parameters information for this Enzyme
- A new technique for the analysis of metabolic pathways of cytidine analogues and cytidine deaminase activities in cells.
- Cytidine deaminase status as a marker of response to azacytidine treatment in MDS and AML patients.
- Cytidine deaminase enzyme activity is a predictive biomarker in gemcitabine-treated cancer patients.
- Activation-induced cytidine deaminase an antibody diversification enzyme interacts with chromatin modifier UBN1 in B-cells.
- Enhanced single-base mutation diversity by the combination of cytidine deaminase with DNA-repairing enzymes in yeast.
- Mutagenesis system by fusing cytidine deaminase with T7 promoter in yeast
- Necessity of HuR/ELAVL1 for the activation-induced cytidine deaminase-dependent decrease in topoisomerase 1 in antibody diversification.
- The APOBEC3B cytidine deaminase is an adenovirus restriction factor.
- Replication cycle timing determines phage sensitivity to a cytidine deaminase toxin/antitoxin bacterial defense system.
- The cytidine deaminase APOBEC3A is required for large ribosomal subunit biogenesis
- [Activation-induced cytidine deaminase (AID) involved in the regulation of B cell immune senescence].