6IVE

Molecular structure of a thermostable and a Zinc ion binding gamma-class carbonic anhydrase

6IVE の概要

• エントリーDOI: 10.2210/pdb6ive/pdb
• 分子名称: Ferripyochelin-binding protein, ZINC ION, PHOSPHATE ION, ... (4 entities in total)
• 機能のキーワード: gamma-class carbonic anhydrase metal binding protein, metal binding protein
• 由来する生物種: Thermus thermophilus (strain HB8 / ATCC 27634 / DSM 579)
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 105825.03

構造登録者

Wang, W.M.,Wang, H.F. (登録日: 2018-12-03, 公開日: 2019-04-03, 最終更新日: 2023-11-22)

主引用文献

Wang, W.,Zhang, Y.,Wang, L.,Jing, Q.,Wang, X.,Xi, X.,Zhao, X.,Wang, H.
Molecular structure of thermostable and zinc-ion-binding gamma-class carbonic anhydrases.
Biometals, 32:317-328, 2019

PubMed Abstract: The γ-class carbonic anhydrases (γ-CAs) mainly come from methanogens methane-producing bacteria that grow in hot springs and catalyze the interconversion of carbon dioxide and water to bicarbonate and protons. Here, the γ-CA from Thermus thermophilus HB8 (γ-TtCA) was expressed and purified, its crystal structure was determined at 2.3 Å resolution in space group P1. The asymmetric unit contains two trimers and six catalytic Zn. In general, the fold of the protein is similar to those of homologous enzymes from Geobacillus Kaustophilus, Bacillus Cereus, Methanosarcina Thermophila and others. Each monomer comprises a triangular prism-like structure consisting of a left-handed β-helix and a C-terminal α-helix. The catalytic Zn bound to three histidines and a phosphate radical in a tetrahedral fashion. It is located at the interface between the two monomers. Inductively coupled plasma mass spectrometry measurements further suggest that the molar ratio of zinc ions and protein molecules is 1:1. The structure revealed a novel different region situated between the left-handed β-helix and the C-terminal α-helix. Compared to previously reported structures, half of the C-terminal α-helix was replaced with a long loop in this structure. The purified γ-TtCA exhibits no significant carbonic anhydrase activity compared to α-class carbonic anhydrases. This study provides insight into the structural diversity of γ-CAs with potential function for γ-CAs.

PubMed: 30895492
DOI: 10.1007/s10534-019-00190-8

実験手法

X-RAY DIFFRACTION (2.3 Å)