Structural diversity of F/sub 430/ from methanobacterium thermoautotrophicum. A nickel x-ray absorption spectroscopic study

Journal Article · Wed May 28 00:00:00 EDT 1986 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00271a060· OSTI ID:5430146

Eidsness, M K; Sullivan, R J; Schwartz, J R; Hartzell, P L; Wolfe, R S; Flank, A M; Cramer, S P; Scott, R A

Nickel metalloenzymes have been found in all methane-producing bacteria examined. Two hydrogenases from Methanobacterium thermoautotrophicum contain nickel which has been shown to be coordinated by S-containing ligands in one form. A compound called F/sub 430/ has been isolated from M. thermoautotrophicum, strain ..delta..H, and has been identified as the Ni-containing prosthetic group in protein component C of the S-methyl coenzyme-M reductase system. F/sub 430/ has been established to have a Ni(II)-tetrapyrrole structure, constituting the only known biological example of nickel in a tetrahydro reduced corphine. The detailed mechanistic role of F/sub 430/ in methyl group reduction has not been identified. We report here a Ni x-ray absorption spectroscopic (XAS) study of several forms of F/sub 430/ and component C isolated from M. thermoautotrophicum, strain ..delta..H. These preliminary results indicate that free F/sub 430/ is structurally distinct from the F/sub 430/-containing protein. Also, depending upon the conditions used, extraction of F/sub 430/ from the protein yields at least two structurally distinct forms, one similar to that in the intact protein and one similar to free F/sub 430/. Analysis of the extended x-ray absorption fine structure (EXAFS) data and comparison with a number of structurally characterized Ni(II) complexes provide evidence that the flexibility of the tetrapyrrole is responsible for the different structural forms.

• Research Organization: Univ. of Illinois, Urbana
• OSTI ID: 5430146
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 108:11; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
AZOLES
BACTERIA
COMPLEXES
DATA
ENZYMES
EXPERIMENTAL DATA
HETEROCYCLIC COMPOUNDS
INFORMATION
LIGANDS
METHANOTROPHIC BACTERIA
MICROORGANISMS
MOLECULAR STRUCTURE
NICKEL COMPLEXES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PYRROLES
SPECTROSCOPY
TRANSITION ELEMENT COMPLEXES
X-RAY SPECTROSCOPY