Genetic Analysis of Bifunctional Genes from Rumen Bacterium

Authors : Emin ÖZKÖSE, İsmail AKYOL, Ercan EFE, M Sait EKİNCİ

Pages : 91-97

View : 25 | Download : 11

Publication Date : 2004-12-01

Article Type : Research Paper

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 b-insert ignore into journalissuearticles values(1,3-1,4);-glucanase insert ignore into journalissuearticles values(xynD); activities with 3 domains insert ignore into journalissuearticles values(A, B, C);. The amino-terminal domain insert ignore into journalissuearticles values(A); is related to family G xylanase while the carboxy-terminal domain insert ignore into journalissuearticles values(C); is related to family 16 b-insert ignore into journalissuearticles values(1,3-1,4);-glucanase. These 2 domains are connected by a region insert ignore into journalissuearticles values(B); of unknown function. Deletion of domain B leads to increased thermosensitivity of the enzyme and also in a 2-3-fold increase in b-insert ignore into journalissuearticles values(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 non-catalytic domains from other sources also showed xylan binding properties. Therefore, these domains are also called xylan binding domains insert ignore into journalissuearticles values(XBDs);.
Keywords : Ruminococcus flavefaciens, xylanase, thermostabilizing domain, rumen bacteria