Analysis of Functional Domains on Glutamate Synthase

Authors : Barbaros NALBANTOĞLU

Pages : 197-214

View : 16 | Download : 8

Publication Date : 2000-12-01

Article Type : Research Paper

Abstract :Glutamate synthases insert ignore into journalissuearticles values(GOGAT); were analyzed to identify the functional binding domains of the substrate insert ignore into journalissuearticles values(glutamine); and cofactors insert ignore into journalissuearticles values(FMN, NADinsert ignore into journalissuearticles values(P);H, FAD, [3Fe-4S]1+,0 and [4Fe-4S]2+,1+ clusters and ferredoxin); on this enzyme. The published amino acid sequences of six different NADinsert ignore into journalissuearticles values(P);H-dependent GOGATs insert ignore into journalissuearticles values(NADinsert ignore into journalissuearticles values(P);H-GOGAT); and ten different ferredoxin-dependent GOGATs insert ignore into journalissuearticles values(Fd-GOGAT); were used for this analysis. The amino acid sequences of these sixteen GOGATs were compared with the amino acid sequences of aminotransferases for glutamine, flavoproteins for FMN, flavoproteins and pyridine-nucleotide-dependent enzymes for FAD and NADinsert ignore into journalissuearticles values(P);H, iron-sulfur proteins for [3Fe-4S] 1+,0 and [4Fe-4S]2+,1+ clusters and ferredoxin-dependent enzymes for ferredoxin. It was determined that Fd-GOGAT has one domain each for glutamine, FMN and [3Fe-4S]1+,0 cluster and two domains each for FAD and ferredoxin; the NADPH-GOGAT a subunit has the same domains as Fd-GOGAT except for the ferredoxin domains, and b subunit has one domain each for NADPH and FAD and two domains for two [4Fe-4S]2+,1+ clusters; NADH-GOGAT has the same domains as NADPH-GOGAT.
Keywords : Glutamate synthase, glutamine, FMN, FAD, NAD P, H, iron sulfur cluster, ferredoxin, binding domain