6ONC

Crystal structure of Desulfovibrio vulgaris carbon monoxide dehydrogenase produced without CooC, as-isolated

6ONC の概要

• エントリーDOI: 10.2210/pdb6onc/pdb
• 分子名称: Carbon monoxide dehydrogenase, IRON/SULFUR CLUSTER, FE(4)-NI(1)-S(4) CLUSTER, ... (9 entities in total)
• 機能のキーワード: nickel-iron-sulfur (ni-fe-s) cluster, iron-sulfur (fe-s) cluster, metalloenzyme, oxidoreductase
• 由来する生物種: Desulfovibrio vulgaris
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 275028.13

構造登録者

Wittenborn, E.C.,Cohen, S.E.,Drennan, C.L. (登録日: 2019-04-21, 公開日: 2019-07-24, 最終更新日: 2023-10-11)

主引用文献

Wittenborn, E.C.,Cohen, S.E.,Merrouch, M.,Leger, C.,Fourmond, V.,Dementin, S.,Drennan, C.L.
Structural insight into metallocofactor maturation in carbon monoxide dehydrogenase.
J.Biol.Chem., 294:13017-13026, 2019

PubMed Abstract: The nickel-dependent carbon monoxide dehydrogenase (CODH) employs a unique heterometallic nickel-iron-sulfur cluster, termed the C-cluster, to catalyze the interconversion of CO and CO Like other complex metalloenzymes, CODH requires dedicated assembly machinery to form the fully intact and functional C-cluster. In particular, nickel incorporation into the C-cluster depends on the maturation factor CooC; however, the mechanism of nickel insertion remains poorly understood. Here, we compare X-ray structures (1.50-2.48 Å resolution) of CODH from (CODH) heterologously expressed in either the absence (CODH) or presence (CODH) of co-expressed CooC. We find that the C-cluster of CODH is fully loaded with iron but does not contain any nickel. Interestingly, the so-called unique iron ion (Fe) occupies both its canonical site (80% occupancy) and the nickel site (20% occupancy), with addition of reductant causing further mismetallation of the nickel site (60% iron occupancy). We also demonstrate that a CODH variant that lacks a surface-accessible iron-sulfur cluster (the D-cluster) has a C-cluster that is also replete in iron but lacks nickel, despite co-expression with CooC. In this variant, all Fe is in its canonical location, and the nickel site is empty. This D-cluster-deficient CODH is inactive despite attempts to reconstitute it with nickel. Taken together, these results suggest that an empty nickel site is not sufficient for nickel incorporation. Based on our findings, we propose a model for C-cluster assembly that requires both CooC and a functioning D-cluster, involves precise redox-state control, and includes a two-step nickel-binding process.

PubMed: 31296570
DOI: 10.1074/jbc.RA119.009610

実験手法

X-RAY DIFFRACTION (1.5 Å)