6H9E

Structure of glutamate mutase reconstituted with homo-coenzyme B12

6H9E の概要

• エントリーDOI: 10.2210/pdb6h9e/pdb
• 分子名称: Glutamate mutase sigma subunit, Glutamate mutase epsilon subunit, COBALAMIN, ... (7 entities in total)
• 機能のキーワード: coenzyme b12, co-c-bond, radical reaction, tim-barrel, rossman-fold, isomerase
• 由来する生物種: Clostridium cochlearium; 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 140842.17

構造登録者

Gruber, K.,Csitkovits, V.,Kratky, C. (登録日: 2018-08-03, 公開日: 2019-08-14, 最終更新日: 2024-01-31)

主引用文献

Gruber, K.,Csitkovits, V.,Lyskowski, A.,Kratky, C.,Krautler, B.
Structure-Based Demystification of Radical Catalysis by a Coenzyme B 12 Dependent Enzyme-Crystallographic Study of Glutamate Mutase with Cofactor Homologues.
Angew.Chem.Int.Ed.Engl., 61:e202208295-e202208295, 2022

PubMed Abstract: Catalysis by radical enzymes dependent on coenzyme B (AdoCbl) relies on the reactive primary 5'-deoxy-5'adenosyl radical, which originates from reversible Co-C bond homolysis of AdoCbl. This bond homolysis is accelerated roughly 10 -fold upon binding the enzyme substrate. The structural basis for this activation is still strikingly enigmatic. As revealed here, a displaced firm adenosine binding cavity in substrate-loaded glutamate mutase (GM) causes a structural misfit for intact AdoCbl that is relieved by the homolytic Co-C bond cleavage. Strategically interacting adjacent adenosine- and substrate-binding protein cavities provide a tight caged radical reaction space, controlling the entire radical path. The GM active site is perfectly structured for promoting radical catalysis, including "negative catalysis", a paradigm for AdoCbl-dependent mutases.

PubMed: 35793207
DOI: 10.1002/anie.202208295

実験手法

X-RAY DIFFRACTION (1.82 Å)