Download MendeleyCrystal structure of a new type of NADPH-dependent quinone oxidoreductase (QOR2) from Escherichia coli
Kim, I.K., Yim, H.S., Kim, M.K., Kim, D.W., Kim, Y.M., Cha, S.S., Kang, S.O.(2008) J Mol Biol 379: 372-384
- PubMed: 18455185
- DOI: https://doi.org/10.1016/j.jmb.2008.04.003
- Primary Citation of Related Structures:
2ZCU, 2ZCV - PubMed Abstract:
Escherichia coli QOR2 [NAD(P)H-dependent quinone oxidoreductase; a ytfG gene product], which catalyzes two-electron reduction of methyl-1,4-benzoquinone, is a new type of quinone-reducing enzyme with distinct primary sequence and oligomeric conformation from previously known quinone oxidoreductases. The crystal structures of native QOR2 and the QOR2-NADPH (nicotinamide adenine dinucleotide phosphate, reduced form) complex reveal that QOR2 consists of two domains (N-domain and C-domain) resembling those of NmrA, a negative transcriptional regulator that belongs to the short-chain dehydrogenase/reductase family. The N-domain, which adopts the Rossmann fold, provides a platform for NADPH binding, whereas the C-domain, which contains a hydrophobic pocket connected to the NADPH-binding site, appears to play important roles in substrate binding. Asn143 near the NADPH-binding site has been identified to be involved in substrate binding and catalysis from structural and mutational analyses. Moreover, compared with wild-type strain, the qor2-overexpressing strain shows growth retardation and remarkable decrease in several enzymes involved in carbon metabolism, suggesting that QOR2 could play some physiological roles in addition to quinone reduction.
Organizational Affiliation:
Laboratory of Biophysics, School of Biological Sciences and Institute of Microbiology, Seoul National University, Seoul 151-742, Republic of Korea.
