The research proposed herein seeks to determine the structural organization and function of the MoFe protein of Azotobacter vinelandii nitrogenase and how the protein is organized to deliver the required reducing equivalents to substrate. The project seeks funding for biochemical and biophysical experiments on an entity called the FeMo- cluster which may represent the inorganic portion of the FeMo-co site, on a form of the MoFe protein which only contains the [4Fe-4S]-type clusters, on the interaction of the Fe protein/MgATP complex with that protein and on the process of inserting FeMo-co into the protein. These experiments are designed to determine the chemical, redox and physical properties of each component of the MoFe holoprotein and how they interact with each other and other components of the nitrogenase system. This research project will determine the individual responsibilities of the various portions of the MoFe for catalysis and will thus delineate the internal molecular workings of the MoFe protein. Such information will be invaluable in attempts to enhance biological nitrogen fixation or to duplicate it synthetically for agronomic benefit. Increased fixed nitrogen ability equates to increased protein supply, which is a significant factor in good nutrition and health.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
1R01GM043144-01
Application #
3302102
Study Section
Metallobiochemistry Study Section (BMT)
Project Start
1989-12-01
Project End
1994-11-30
Budget Start
1989-12-01
Budget End
1990-11-30
Support Year
1
Fiscal Year
1990
Total Cost
Indirect Cost
Name
University of California Irvine
Department
Type
Schools of Arts and Sciences
DUNS #
161202122
City
Irvine
State
CA
Country
United States
Zip Code
92697
Ribbe, Markus W; Hu, Yilin; Guo, Maolin et al. (2002) The FeMoco-deficient MoFe protein produced by a nifH deletion strain of Azotobacter vinelandii shows unusual P-cluster features. J Biol Chem 277:23469-76
Guo, Maolin; Sulc, Filip; Ribbe, Markus W et al. (2002) Direct assessment of the reduction potential of the [4Fe-4S](1+/0) couple of the Fe protein from Azotobacter vinelandii. J Am Chem Soc 124:12100-1
Ribbe, M W; Burgess, B K (2001) The chaperone GroEL is required for the final assembly of the molybdenum-iron protein of nitrogenase. Proc Natl Acad Sci U S A 98:5521-5
Strop, P; Takahara, P M; Chiu, H et al. (2001) Crystal structure of the all-ferrous [4Fe-4S]0 form of the nitrogenase iron protein from Azotobacter vinelandii. Biochemistry 40:651-6
Frank, P; Angove, H C; Burgess, B K et al. (2001) Determination of ligand binding constants for the iron-molybdenum cofactor of nitrogenase: monomers, multimers, and cooperative behavior. J Biol Inorg Chem 6:683-97
Ribbe, M W; Bursey, E H; Burgess, B K (2000) Identification of an Fe protein residue (Glu146) of Azotobacter vinelandii nitrogenase that is specifically involved in FeMo cofactor insertion. J Biol Chem 275:17631-8
Kim, S; Burgess, B K (1996) Evidence for the direct interaction of the nifW gene product with the MoFe protein. J Biol Chem 271:9764-70
Ma, L; Brosius, M A; Burgess, B K (1996) Construction of a form of the MoFe protein of nitrogenase that accepts electrons from the Fe protein but does not reduce substrate. J Biol Chem 271:10528-32
Ma, L; Gavini, N; Liu, H I et al. (1994) Large scale isolation and characterization of the molybdenum-iron cluster from nitrogenase. J Biol Chem 269:18007-15
Chen, L; Gavini, N; Tsuruta, H et al. (1994) MgATP-induced conformational changes in the iron protein from Azotobacter vinelandii, as studied by small-angle x-ray scattering. J Biol Chem 269:3290-4

Showing the most recent 10 out of 17 publications