Format

Send to

Choose Destination
See comment in PubMed Commons below
Proc Natl Acad Sci U S A. 2001 Aug 14;98(17):9521-6. Epub 2001 Aug 7.

Mapping the interactions between flavodoxin and its physiological partners flavodoxin reductase and cobalamin-dependent methionine synthase.

Author information

1
Biophysics Research Division and Department of Biological Chemistry, University of Michigan, Ann Arbor 48109-1055, USA.

Abstract

Flavodoxins are electron-transfer proteins that contain the prosthetic group flavin mononucleotide. In Escherichia coli, flavodoxin is reduced by the FAD-containing protein NADPH:ferredoxin (flavodoxin) oxidoreductase; flavodoxins serve as electron donors in the reductive activation of anaerobic ribonucleotide reductase, biotin synthase, pyruvate formate lyase, and cobalamin-dependent methionine synthase. In addition, domains homologous to flavodoxin are components of the multidomain flavoproteins cytochrome P450 reductase, nitric oxide synthase, and methionine synthase reductase. Although three-dimensional structures are known for many of these proteins and domains, very little is known about the structural aspects of their interactions. We address this issue by using NMR chemical shift mapping to identify the surfaces on flavodoxin that bind flavodoxin reductase and methionine synthase. We find that these physiological partners bind to unique overlapping sites on flavodoxin, precluding the formation of ternary complexes. We infer that the flavodoxin-like domains of the cytochrome P450 reductase family form mutually exclusive complexes with their electron-donating and -accepting partners, complexes that require conformational changes for interconversion.

PMID:
11493691
PMCID:
PMC55485
DOI:
10.1073/pnas.171168898
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Support Center