Characterization of Methyl- and Acetyl-Ni Intermediates in Acetyl CoA Synthase Formed during Anaerobic CO 2 and CO Fixation.

Autor: Can M; Department of Biochemistry, Faculty of Pharmacy, Ankara Medipol University, Ankara 06050, Turkey., Abernathy MJ; Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States., Wiley S; Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States., Griffith C; Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States., James CD; Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States., Xiong J; Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States., Guo Y; Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States., Hoffman BM; Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States., Ragsdale SW; Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States., Sarangi R; Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States.
Jazyk: angličtina
Zdroj: Journal of the American Chemical Society [J Am Chem Soc] 2023 Jun 28; Vol. 145 (25), pp. 13696-13708. Date of Electronic Publication: 2023 Jun 12.
DOI: 10.1021/jacs.3c01772
Abstrakt: The Wood-Ljungdahl Pathway is a unique biological mechanism of carbon dioxide and carbon monoxide fixation proposed to operate through nickel-based organometallic intermediates. The most unusual steps in this metabolic cycle involve a complex of two distinct nickel-iron-sulfur proteins: CO dehydrogenase and acetyl-CoA synthase (CODH/ACS). Here, we describe the nickel-methyl and nickel-acetyl intermediates in ACS completing the characterization of all its proposed organometallic intermediates. A single nickel site (Ni p ) within the A cluster of ACS undergoes major geometric and redox changes as it transits the planar Ni p , tetrahedral Ni p -CO and planar Ni p -Me and Ni p -Ac intermediates. We propose that the Ni p intermediates equilibrate among different redox states, driven by an electrochemical-chemical (EC) coupling process, and that geometric changes in the A-cluster linked to large protein conformational changes control entry of CO and the methyl group.
Databáze: MEDLINE
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