1I6O

CRYSTAL STRUCTURE OF E. COLI BETA CARBONIC ANHYDRASE (ECCA)

1I6O の概要

• エントリーDOI: 10.2210/pdb1i6o/pdb
• 関連するPDBエントリー: 1I6P
• 分子名称: CARBONIC ANHYDRASE, ZINC ION (3 entities in total)
• 機能のキーワード: carbonic anhydrase, metalloenzyme, zinc coordination, ph-dependent activity, mad phasing, lyase
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 50861.33

構造登録者

Cronk, J.D.,Endrizzi, J.A.,Cronk, M.R.,O'Neill, J.W.,Zhang, K.Y.J. (登録日: 2001-03-02, 公開日: 2001-05-09, 最終更新日: 2024-10-16)

主引用文献

Cronk, J.D.,Endrizzi, J.A.,Cronk, M.R.,O'neill, J.W.,Zhang, K.Y.
Crystal structure of E. coli beta-carbonic anhydrase, an enzyme with an unusual pH-dependent activity.
Protein Sci., 10:911-922, 2001

PubMed Abstract: Carbonic anhydrases fall into three distinct evolutionary and structural classes: alpha, beta, and gamma. The beta-class carbonic anhydrases (beta-CAs) are widely distributed among higher plants, simple eukaryotes, eubacteria, and archaea. We have determined the crystal structure of ECCA, a beta-CA from Escherichia coli, to a resolution of 2.0 A. In agreement with the structure of the beta-CA from the chloroplast of the red alga Porphyridium purpureum, the active-site zinc in ECCA is tetrahedrally coordinated by the side chains of four conserved residues. These results confirm the observation of a unique pattern of zinc ligation in at least some beta-CAS: The absence of a water molecule in the inner coordination sphere is inconsistent with known mechanisms of CA activity. ECCA activity is highly pH-dependent in the physiological range, and its expression in yeast complements an oxygen-sensitive phenotype displayed by a beta-CA-deletion strain. The structural and biochemical characterizations of ECCA presented here and the comparisons with other beta-CA structures suggest that ECCA can adopt two distinct conformations displaying widely divergent catalytic rates.

PubMed: 11316870
DOI: 10.1110/ps.46301

実験手法

X-RAY DIFFRACTION (2.2 Å)