1zab

Crystal Structure of Mouse Cytidine Deaminase Complexed with 3-DeazauridineCrystal Structure of Mouse Cytidine Deaminase Complexed with 3-Deazauridine

Structural highlights 1zab is a 4 chain structure with sequence from Lk3 transgenic mice. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: , , Related: 2fr5, 2fr6 Activity: Cytidine deaminase, with EC number 3.5.4.5 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [CDD_MOUSE] This enzyme scavenge exogenous and endogenous cytidine and 2'-deoxycytidine for UMP synthesis (By similarity). 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 Cytidine deaminase (CDA) is a zinc-dependent enzyme that catalyzes the deamination of cytidine or deoxycytidine to form uridine or deoxyuridine. Here we present the crystal structure of mouse CDA (MmCDA), complexed with either tetrahydrouridine (THU), 3-deazauridine (DAU), or cytidine. In the MmCDA-DAU complex, it clearly demonstrates that cytidine is distinguished from uridine by its 4-NH(2) group that acts as a hydrogen bond donor. In the MmCDA-cytidine complex, cytidine, unexpectedly, binds as the substrate instead of the deaminated product in three of the four subunits, and in the remaining subunit it binds as the product uridine. Furthermore, the charge-neutralizing Arg68 of MmCDA has also exhibited two alternate conformations, I and II. In conformation I, the only conformation observed in the other structurally known homotetrameric CDAs, Arg68 hydrogen bonds Cys65 and Cys102 to modulate part of their negative charges. However, in conformation II the side chain of Arg68 rotates about 130 degrees around the Cgamma-Cdelta bond and abolishes these hydrogen bonds. The lack of hydrogen bonding may indirectly weaken the zinc-product interaction by increased electron donation from cysteine to the zinc ion, suggesting a novel product-expelling mechanism. On the basis of known structures, structural analysis further reveals two subclasses of homotetrameric CDAs that can be identified according to the position of the charge-neutralizing arginine residue. Implications for CDA-RNA interaction have also been considered. The 1.48 A resolution crystal structure of the homotetrameric cytidine deaminase from mouse.,Teh AH, Kimura M, Yamamoto M, Tanaka N, Yamaguchi I, Kumasaka T Biochemistry. 2006 Jun 27;45(25):7825-33. PMID:16784234 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Deaminase 3D structures

spinqualitylabelsall models 1zab, resolution 2.36Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image