Crystal Structure of ChrR -- A Quinone Reductase with the Capacity to Reduce Chromate

Journal Article · Sun Apr 01 04:00:00 EDT 2012 · PLoS ONE

DOI:https://doi.org/10.1371/journal.pone.0036017· OSTI ID:1049237

Eswaramoorthy, S; Poulain, S; Hienerwadel, R; Bremond, N; Sylvester, M D; Zhang, Y -B; Berthomieu, C; van der Lelie, D; Matin, A

The Escherichia coli ChrR enzyme is an obligatory two-electron quinone reductase that has many applications, such as in chromate bioremediation. Its crystal structure, solved at 2.2 {angstrom} resolution, shows that it belongs to the flavodoxin superfamily in which flavin mononucleotide (FMN) is firmly anchored to the protein. ChrR crystallized as a tetramer, and size exclusion chromatography showed that this is the oligomeric form that catalyzes chromate reduction. Within the tetramer, the dimers interact by a pair of two hydrogen bond networks, each involving Tyr128 and Glu146 of one dimer and Arg125 and Tyr85 of the other; the latter extends to one of the redox FMN cofactors. Changes in each of these amino acids enhanced chromate reductase activity of the enzyme, showing that this network is centrally involved in chromate reduction.

• Research Organization: BROOKHAVEN NATIONAL LABORATORY (BNL)
• Sponsoring Organization: DEFENSE THREAT REDUCTION AGENCY (DTRA)
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 1049237
• Report Number(s): BNL--96913-2012-JA; 400403709
• Journal Information: PLoS ONE, Journal Name: PLoS ONE Journal Issue: 4 Vol. 7; ISSN 1932-6203
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
60 APPLIED LIFE SCIENCES
AMINO ACIDS
BENZOQUINONES
BIOREMEDIATION
CAPACITY
CHROMATES
CHROMATOGRAPHY
CRYSTAL STRUCTURE
DIMERS
ENZYMES
ESCHERICHIA COLI
HYDROGEN
ISOALLOXAZINES
OXIDOREDUCTASES
RESOLUTION