1JTK

Crystal structure of cytidine deaminase from Bacillus subtilis in complex with the inhibitor tetrahydrodeoxyuridine

1JTK の概要

• エントリーDOI: 10.2210/pdb1jtk/pdb
• 分子名称: cytidine deaminase, ZINC ION, TETRAHYDRODEOXYURIDINE, ... (4 entities in total)
• 機能のキーワード: cytidine deaminase, cda, pyrimidine salvage pathway, hydrolase
• 由来する生物種: Bacillus subtilis
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 30329.28

構造登録者

Johansson, E.,Mejlhede, N.,Neuhard, J.,Larsen, S. (登録日: 2001-08-21, 公開日: 2002-04-10, 最終更新日: 2023-10-25)

主引用文献

Johansson, E.,Mejlhede, N.,Neuhard, J.,Larsen, S.
Crystal structure of the tetrameric cytidine deaminase from Bacillus subtilis at 2.0 A resolution.
Biochemistry, 41:2563-2570, 2002

PubMed Abstract: Cytidine deaminases (CDA, EC 3.5.4.5) are zinc-containing enzymes in the pyrimidine salvage pathway that catalyze the formation of uridine and deoxyuridine from cytidine and deoxycytidine, respectively. Two different classes have been identified in the CDA family, a homodimeric form (D-CDA) with two zinc ions per dimer and a homotetrameric form (T-CDA) with four zinc ions per tetramer. We have determined the first structure of a T-CDA from Bacillus subtilis. The active form of T-CDA is assembled of four identical subunits with one active site apiece. The subunit of D-CDA is composed of two domains each exhibiting the same fold as the T-CDA subunits, but only one of them contains zinc in the active site. The similarity results in a conserved structural core in the two CDA forms. An intriguing difference between the two CDA structures is the zinc coordinating residues found at the N-terminal of two alpha-helices: three cysteine residues in the tetrameric form and two cysteine residues and one histidine residue in the dimeric form. The role of the zinc ion is to activate a water molecule and thereby generate a hydroxide ion. How the zinc ion in T-CDA surrounded with three negatively charged residues can create a similar activity of T-CDA compared to D-CDA has been an enigma. However, the structure of T-CDA reveals that the negative charge caused by the three ligands is partly neutralized by (1) an arginine residue hydrogen-bonded to two of the cysteine residues and (2) the dipoles of two alpha-helices.

PubMed: 11851403
DOI: 10.1021/bi011849a

実験手法

X-RAY DIFFRACTION (2.04 Å)