title: Specific arrangement of three amino acid residues for flavin-binding barrel structures in NADH-cytochrome b5 reductase and the other flavin-dependent reductases.
abstract: The structure of NADH-cytochrome b5 reductase from pig liver microsomes has been refined to a crystallographic R factor of 0.223 at 2.4 A resolution. A structural comparison between the flavin-binding beta barrel domain of NADH-cytochrome b5 reductase and those of the other flavin-dependent reductases, ferredoxin-NADP+ reductase, phthalate dioxygenase reductase and nitrate reductase, indicated that the overall barrel foldings are similar to each other and that the specific arrangement of three amino acid residues (Arg, Tyr and Ser/Thr) is usually necessary for flavin-binding. These conserved residues overlap each other in their three-dimensional structures and stabilize the flavin-binding site in the four flavin-dependent reductases.
authors.affiliation: Research Laboratory of Resources Utilization, Tokyo Institute of Technology, Yokohama, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Nishida
authors.forename: K
authors.initials: K
authors.lastname: Inaka
authors.forename: K
authors.initials: K
authors.lastname: Miki
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017124:Conserved Sequence / Q000235:genetics*; D018360:Crystallography, X-Ray; D003579:Cytochrome Reductases / Q000737:chemistry* / Q000378:metabolism; D042966:Cytochrome-B(5) Reductase; D005415:Flavins / Q000378:metabolism*; D008862:Microsomes, Liver / Q000201:enzymology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010088:Oxidoreductases / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D016415:Sequence Alignment; D013552:Swine
chemical_list: D005415:Flavins; D010088:Oxidoreductases; D003579:Cytochrome Reductases; D042966:Cytochrome-B(5) Reductase