tailieunhanh - Analysis of functional domains on glutamate synthase

Glutamate synthases (GOGAT) were analyzed to identify the functional binding domains of the substrate (glutamine) and cofactors (FMN, NAD(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 NAD(P)Hdependent GOGATs (NAD(P)H-GOGAT) and ten different ferredoxin-dependent GOGATs (Fd-GOGAT) were used for this analysis. | Turk J Biol 24 (2000) 197–213 © TÜBİTAK Review Article Analysis of Functional Domains on Glutamate Synthase Barbaros NALBANTOĞLU Department of Biochemistry, Faculty of Sciences and Arts, Atatürk University, Erzurum-TURKEY Received: Abstract: Glutamate synthases (GOGAT) were analyzed to identify the functional binding domains of 1+,0 and [4Fe-4S]2+,1+ the substrate (glutamine) and cofactors (FMN, NAD(P)H, FAD, [3Fe-4S] clusters and ferredoxin) on this enzyme. The published amino acid sequences of six different NAD(P)Hdependent GOGATs (NAD(P)H-GOGAT) and ten different ferredoxin-dependent GOGATs (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 NAD(P)H, iron-sulfur proteins for [3Fe4S]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 α subunit has the same domains as FdGOGAT except for the ferredoxin domains, and β 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 NADPHGOGAT. Key Words: Glutamate synthase, glutamine, FMN, FAD, NAD(P)H, iron-sulfur cluster, ferredoxin, binding domain. Glutamat Sentaz Üzerindeki Fonksiyonel Bölgelerin Analizi Özet: Glutamat sentazlar (GOGAT), bu enzim üzerindeki substrat (glutamin) ve kofaktörlerin (FMN, NAD(P)H, FAD, [3Fe-4S]1+,0 ve [4Fe-4S]2+,1+ kümeleri ve ferredoksin) fonksiyonel bağlanma bölgelerini belirlemek için analiz edildi. Altı farklı NAD(P)H’a bağımlı GOGAT (NAD(P)H-GOGAT)’ın ve on farklı ferredoksine bağımlı GOGAT (Fd-GOGAT)’ın yayınlanmış amino asit sıraları bu analiz için kullanıldı. Bu onaltı GOGAT’ın amino asit sırası glutamin için .