3rn6 | pdb_00003rn6

Crystal structure of Cytosine Deaminase from Escherichia Coli complexed with zinc and isoguanine

spinqualitylabelsall models 3rn6, resolution 2.25Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3rn6 is a 1 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: IGA, PXN, ZN Related: 3o7u Gene: codA, b0337, JW0328 (Escherichia coli) Activity: Cytosine deaminase, with EC number 3.5.4.1 Resources: FirstGlance, OCA, RCSB, PDBsum Publication Abstract from PubMed Cytosine deaminase (CDA) from Escherichia coli was shown to catalyze the deamination of isoguanine (2-oxoadenine) to xanthine. Isoguanine is an oxidation product of adenine in DNA that is mutagenic to the cell. The isoguanine deaminase activity in E. coli was partially purified by ammonium sulfate fractionation, gel filtration, and anion exchange chromatography. The active protein was identified by peptide mass fingerprint analysis as cytosine deaminase. The kinetic constants for the deamination of isoguanine at pH 7.7 are as follows: k(cat) = 49 s(-1), K(m) = 72 muM, and k(cat)/K(m) = 6.7 x 10(5) M(-1) s(-1). The kinetic constants for the deamination of cytosine are as follows: k(cat) = 45 s(-1), K(m) = 302 muM, and k(cat)/K(m) = 1.5 x 10(5) M(-1) s(-1). Under these reaction conditions, isoguanine is the better substrate for cytosine deaminase. The three-dimensional structure of CDA was determined with isoguanine in the active site. Rescue of the orphan enzyme isoguanine deaminase.,Hitchcock DS, Fedorov AA, Fedorov EV, Dangott LJ, Almo SC, Raushel FM Biochemistry. 2011 Jun 28;50(25):5555-7. Epub 2011 Jun 7. PMID:21604715 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Deaminase

Proteopedia Page Contributors and Editors (what is this?)

OCA