3RN6

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

3RN6 の概要

• エントリーDOI: 10.2210/pdb3rn6/pdb
• 関連するPDBエントリー: 3O7U
• 分子名称: Cytosine deaminase, (2S)-1-[3-{[(2R)-2-hydroxypropyl]oxy}-2,2-bis({[(2R)-2-hydroxypropyl]oxy}methyl)propoxy]propan-2-ol, ZINC ION, ... (5 entities in total)
• 機能のキーワード: amidohydrolase fold, cytosine deaminase, isoguanine, hydrolase
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 48295.19

構造登録者

Fedorov, A.A.,Fedorov, E.V.,Hitchcock, D.S.,Raushel, F.M.,Almo, S.C. (登録日: 2011-04-22, 公開日: 2011-08-24, 最終更新日: 2023-09-13)

主引用文献

Hitchcock, D.S.,Fedorov, A.A.,Fedorov, E.V.,Dangott, L.J.,Almo, S.C.,Raushel, F.M.
Rescue of the orphan enzyme isoguanine deaminase.
Biochemistry, 50:5555-5557, 2011

PubMed Abstract: 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 μM, and k(cat)/K(m) = 6.7 × 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 μM, and k(cat)/K(m) = 1.5 × 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.

PubMed: 21604715
DOI: 10.1021/bi200680y

実験手法

X-RAY DIFFRACTION (2.255 Å)