Download MendeleyThree-dimensional structure of AzoR from Escherichia coli. An oxidereductase conserved in microorganisms
Ito, K., Nakanishi, M., Lee, W.C., Sasaki, H., Zenno, S., Saigo, K., Kitade, Y., Tanokura, M.(2006) J Biol Chem 281: 20567-20576
- PubMed: 16684776
- DOI: https://doi.org/10.1074/jbc.M513345200
- Primary Citation of Related Structures:
1V4B, 2D5I - PubMed Abstract:
The crystal structure of AzoR (azoreductase) has been determined in complex with FMN for two different crystal forms at 1.8 and 2.2 A resolution. AzoR is an oxidoreductase isolated from Escherichia coli as a protein responsible for the degradation of azo compounds. This enzyme is an FMN-dependent NADH-azoreductase and catalyzes the reductive cleavage of azo groups by a ping-pong mechanism. The structure suggests that AzoR acts in a homodimeric state forming the two identical catalytic sites to which both monomers contribute. The structure revealed that each monomer of AzoR has a flavodoxin-like structure, without the explicit overall amino acid sequence homology. Superposition of the structures from the two different crystal forms revealed the conformational change and suggested a mechanism for accommodating substrates of different size. Furthermore, comparison of the active site structure with that of NQO1 complexed with substrates provides clues to the possible substrate-binding mechanism of AzoR.
Organizational Affiliation:
Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
