3ijf

Crystal structure of cytidine deaminase from Mycobacterium tuberculosis

spinqualitylabelsall models 3ijf, resolution 1.99Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3ijf is a 1 chain structure with sequence from Mycobacterium tuberculosis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.99Å Ligands: ZN Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function CDD_MYCTU Recycles cytidine and 2-deoxycytidine for uridine and 2-deoxyuridine synthesis, respectively. Catalyzes the hydrolytic deamination of cytidine and 2-deoxycytidine to form, respectively, uridine and 2-deoxyuridine. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed The emergence of drug-resistant strains of Mycobacterium tuberculosis, the causative agent of tuberculosis, has exacerbated the treatment and control of this disease. Cytidine deaminase (CDA) is a pyrimidine salvage pathway enzyme that recycles cytidine and 2'-deoxycytidine for uridine and 2'-deoxyuridine synthesis, respectively. A probable M. tuberculosis CDA-coding sequence (cdd, Rv3315c) was cloned, sequenced, expressed in Escherichia coli BL21(DE3), and purified to homogeneity. Mass spectrometry, N-terminal amino acid sequencing, gel filtration chromatography, and metal analysis of M. tuberculosis CDA (MtCDA) were carried out. These results and multiple sequence alignment demonstrate that MtCDA is a homotetrameric Zn(2+)-dependent metalloenzyme. Steady-state kinetic measurements yielded the following parameters: K(m)=1004 microM and k(cat)=4.8s(-1) for cytidine, and K(m)=1059 microM and k(cat)=3.5s(-1) for 2'-deoxycytidine. The pH dependence of k(cat) and k(cat)/K(M) for cytidine indicate that protonation of a single ionizable group with apparent pK(a) value of 4.3 abolishes activity, and protonation of a group with pK(a) value of 4.7 reduces binding. MtCDA was crystallized and crystal diffracted at 2.0 A resolution. Analysis of the crystallographic structure indicated the presence of a Zn(2+) coordinated by three conserved cysteines and the structure exhibits the canonical cytidine deaminase fold. Structural and functional analyses of Mycobacterium tuberculosis Rv3315c-encoded metal-dependent homotetrameric cytidine deaminase.,Sanchez-Quitian ZA, Schneider CZ, Ducati RG, de Azevedo WF Jr, Bloch C Jr, Basso LA, Santos DS J Struct Biol. 2010 Mar;169(3):413-23. Epub 2009 Dec 24. PMID:20035876 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Deaminase 3D structures

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