TAILIEUCHUNG - Genetic analysis of bifunctional genes from Rumen bacterium

Deletion of domain B of the xynD gene was performed and the nucleotide sequence of this domain was compared with other enzyme sequences to reveal its function. Ruminococcus flavefaciens DNA fragment encodes xylanase and β-(1,3-1,4)-glucanase (xynD) activities with 3 domains (A, B, C). | Turk J Biol 28 (2004) 91-97 © TÜB‹TAK Genetic Analysis of Bifunctional Genes from Rumen Bacterium Emin ÖZKÖSE, ‹smail AKYOL, Ercan EFE, M. Sait EK‹NC‹ Department of Animal Science, Faculty of Agriculture, Kahramanmarafl Sütçü ‹mam University, Kahramanmarafl - TURKEY Received: Abstract: Deletion of domain B of the xynD gene was performed and the nucleotide sequence of this domain was compared with other enzyme sequences to reveal its function. Ruminococcus flavefaciens DNA fragment encodes xylanase and β-(1,3-1,4)-glucanase (xynD) activities with 3 domains (A, B, C). The amino-terminal domain (A) is related to family G xylanase while the carboxy-terminal domain (C) is related to family 16 β-(1,3-1,4)-glucanase. These 2 domains are connected by a region (B) of unknown function. Deletion of domain B leads to increased thermosensitivity of the enzyme and also in a 2-3-fold increase in β-(1,3-1,4)-glucanase activity. A survey of the available sequence databases revealed the presence of thermostabilizing domains in numerous other enzymes from various organisms. Although this domain has thermostabilizing properties, it has been proved that similar sequences of noncatalytic domains from other sources also showed xylan binding properties. Therefore, these domains are also called xylan binding domains (XBDs). Key Words: Ruminococcus flavefaciens, xylanase, thermostabilizing domain, rumen bacteria Rumen Bakterisine Ait Çift Fonksiyonlu Genin Genetik Analizi Özet: Bu çalıflmada xynD geninin B bölgesinin fonksiyonunun ortaya çıkarılması için B bölgesinin çıkarılması ve bu bölgenin nükleotid dizisinin di¤er enzimlerin dizileri ile karflılafltırılması yapılmıfltır. Ruminococcus flavefaciens DNA parçası üç bölgeye sahip olup (A, B, C), ksilanaz ve β-(1,3-1,4)-glukanaz (xynD) aktivitelerini kodlamaktadır. Amino-terminal bölge (A) G gen ailesine ait ksilanaz ile iliflkili, buna karflın karboksi-terminal bölge (C) ise 16 gen ailesine ait β-(1,3-1,4)-glukanaz ile .

• Sinh học
• Ruminococcus flavefaciens
• Encodes xylanase
• Thermostabilizing domain
• Rumen bacteria
• XynD gene
• Xylan degradative ability
• Cell associated corboxymethylcellulase
• Incubation in cellobiose
• Enzymes including