Hydrogenase nickel containing

In contrast to the abundance of Fe-proteins, there are only six known nickel-containing enzymes hydrogenase, CO dehydrogenase (CODA), acetyl-CoA synthase (ACS), superoxide dismutase, urease, and S-methyl-CoM methylreductase. Among these enzymes, it exists in very diverse environments, including a dinickel site (urease), a Ni-Fe heterobinuclear site (hydrogenase), a Ni-Fe4S4 heterometallic... 

Alex, L. A., Reeve, J. N., Orme-Johnson, W. H. and Walsh, C. T. (1990) Cloning, sequence determination, and expression of the genes encoding the subunits of the nickel-containing 8-hydroxy-5-deazaflavin reducing hydrogenase from Methanobacterium thermoautotrophicum delta H. Biochemistry, 29, 7237-44. 

Ballantine, S. P. and Boxer, D. H. (1985) Nickel-containing hydrogenase isoenzymes from anaerobically grown Escherichia coli K-12. J. Bacterial., 163, 454-9. 

Graf, E.-G. and Thauer, R. K. (1981) Hydrogenase from Methanobacterium thermoau-totrophicum, a nickel-containing enzyme. FEBS Lett., 36, 165-9. 

Przybyla AE, Robbins J, Menon N, Peck HD Jr. 1992. Structure-function relationships among the nickel-containing hydrogenases. FEMS Microbiol Rev 88 109-35. 

Hydrogenases are not the only nickel-containing enzyme, and researchers must therefore compare the maturation of different nickel proteins to obtain an integrated picture of nickel metabolism. Indeed, similarities between some of the hydrogenase-related nickel-processing proteins with urease and carbon monoxide dehydrogenase maturation factors have been noted, and this has facilitated interpretations of the results for... 

Lissolo T, Choi, ES, LeGall J, Peck HD Jr. 1986. The presence of multiple intrinsic nickel-containing hydrogenases in Desulfovibrio vulgaris Hildenborough. Biochem Biophys Res Commun 139 701-8. 

Electron-transferring subunit, nickel-containing hydrogenases, 38 409-410 Electron transport blue copper proteins, 36 378 NiFe hydrogenase, 47 16-17 Electron volt, 16 73... 

Hydrogenases have been classified into two main types Fe-hydrogenases, which contain iron as the only metal,443 and Ni-hydrogenases, which contain both iron and nickel.444 In a few Ni-hydrogenases a selenocysteine residue replaces a conserved cysteine... 

The soluble hydrogenase from the hydrogen-oxidizing bacterium N. opaca is one of a class of hydrogenases that contain flavin and use nicotinamide adenine dinucleotide (NAD) as electron acceptor. The protein consists of four dissimilar subunits and contains approximately four atoms of nickel, one FMN, three [Fe-4S] clusters, one [2Fe-2S] cluster, and up to one [3Fe-xS] cluster (82). Two of the nickel atoms were readily removed by dialysis, in contrast to the nickel in most hydrogenases. The enzyme would only catalyze electron transfer from hydrogen to NAD if cations, of which Ni2+ is the most effective, were added. In the absence of the cations, the enzyme could be separated as... 

EPR spectra of CO oxidoreductase under non reducing conditions showed a spectrum at g = 2.21, 2.11, and 2.02, which, by analogy with spectra observed in nickel-containing hydrogenases, was attributed to Ni(III) (96). The spectrum was of low intensity and it was not established whether it represents an active state of the enzyme. 

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