Structure of the alpha2epsilon2 Ni-dependent CO dehydrogenase component of the Methanosarcina barkeri acetyl-CoA decarbonylase/synthase complex.
Ni-dependent carbon monoxide dehydrogenases (Ni-CODHs) are a diverse family of enzymes that catalyze reversible CO:CO(2) oxidoreductase activity in acetogens, methanogens, and some CO-using bacteria. Crystallography of Ni-CODHs from CO-using bacteria and acetogens has revealed the overall fold of the Ni-CODH core and has suggested structures for the C cluster that mediates CO:CO(2) interconversion. Despite these advances, the mechanism of CO oxidation has remained elusive. Herein, we report the structure of a distinct class of Ni-CODH from methanogenic archaea: the alpha(2)epsilon(2) component from the alpha(8)beta(8)gamma(8)delta(8)epsilon(8) CODH/acetyl-CoA decarbonylase/synthase complex, an enzyme responsible for the majority of biogenic methane production on Earth. The structure of this Ni-CODH component provides support for a hitherto unobserved state in which both CO and H(2)O/OH(-) bind to the Ni and the exogenous FCII iron of the C cluster, respectively, and offers insight into the structures and functional roles of the epsilon-subunit and FeS domain not present in nonmethanogenic Ni-CODHs.
Gong
Weimin
W
Departments of Biochemistry, Chemistry and Microbiology, and Ohio State Biochemistry Program, Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA.
Hao
Bing
B
Wei
Zhiyi
Z
Ferguson
Donald J
DJ
Tallant
Thomas
T
Krzycki
Joseph A
JA
Chan
Michael K
MK
D000445:Aldehyde Oxidoreductases / Q000737:chemistry*; D001665:Binding Sites; D002248:Carbon Monoxide; D007501:Iron; D007506:Iron-Sulfur Proteins / Q000737:chemistry; D017021:Methanosarcina barkeri / Q000201:enzymology*; D009097:Multienzyme Complexes / Q000737:chemistry*; D009532:Nickel; D011487:Protein Conformation; D014867:Water
D007506:Iron-Sulfur Proteins; D009097:Multienzyme Complexes; D014867:Water; D009532:Nickel; D002248:Carbon Monoxide; D007501:Iron; D000445:Aldehyde Oxidoreductases; C019823:carbon monoxide dehydrogenase