Structure Modeling of Azoreductase AZR and Site-directed Mutagenesis of Its K~(109) Residue
- VernacularTitle:偶氮还原酶AZR的结构及其K~(109)的定点突变研究
- Author:
Guang-Fei LIU
;
Ji-Ti ZHOU
;
Mi ZHOU
;
Jing-Mei LI
;
- Publication Type:Journal Article
- Keywords:
Azoreductase, Homology modeling, Site-directed mutagenesis
- From:
Microbiology
1992;0(05):-
- CountryChina
- Language:Chinese
-
Abstract:
Three-dimensional structure model of azoreductase AZR of Rhodobacter sphaeroides was con- structed using homology modeling method. It is a flavodoxin adopting ?/? structure. Structure alignment of two different types of flavin-dependent azoreductases revealed that they possessed high similarity. Based on sequence and structure analysis, site-directed mutagenesis of K109H and K109A were performed. The opti- mal pH values are pH 6 and pH 9 for K109H and K109A mutant protein, respectively. The optimal tempera- ture (30℃) is not affected by mutagenesis. Positively charged residues at position 109 is necessary for the binding of methyl red, while K109H is not a conserved mutagenesis for the binding of NADPH. K109 may only be involved in the binding of the 2’-phosphate group of NADPH and have no effect on the binding of NADH.
