title: Screening of a xylanase clone from a fosmid library of rumen microbiota in Hu sheep.
abstract: The glycosyl hydrolase family 11, which is responsible for carbohydrate metabolism, was identified in the open reading frame (ORF) 6 of a xylanase positive clone from a fosmid library of rumen microbiota of Hu sheep. A BLASTP search of GenBank revealed that ORF6 encoded a 355-amino acid putative endoxylanase, having 61% similarity (e(-73)) to endo-1,4-β-xylanase of Fibrobacter succinogenes S85 (YP_003250510.1). Predicted with the SWISS-MODEL, there were two separate β-sandwich clusters linked with a high serine containing linker in ORF6. The N-terminal β-sandwich is a novel endoxylanase of the glycosyl hydrolase family 11 with a specific activity of 1150.00 U/mg. The optimal pH and temperature for this enzyme were shown to be pH 5.0 and 50°C, respectively. The C-terminal helped increase the stability of the xylanase but decreased the activity to some degree. The C-terminal β-sandwich could bind avicel, but no conserved domain could be found. It may be a novel carbohydrate-binding module.
authors.affiliation: College of Animal Sciences, Zhejiang University, Hangzhou, China. jiakunwang@zju.edu.cn
authors.forename: Jiakun
authors.initials: J
authors.lastname: Wang
authors.forename: Zhongyuan
authors.initials: Z
authors.lastname: Sun
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhou
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.forename: Jun'an
authors.initials: J
authors.lastname: Ye
authors.forename: Zhenming
authors.initials: Z
authors.lastname: Chen
authors.forename: Jianxin
authors.initials: J
authors.lastname: Liu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D001709:Biotechnology; D002482:Cellulose / Q000378:metabolism; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D004795:Enzyme Stability; D045848:Fibrobacter / Q000201:enzymology / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D054892:Metagenome; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016366:Open Reading Frames; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012417:Rumen / Q000382:microbiology*; D017386:Sequence Homology, Amino Acid; D012756:Sheep / Q000382:microbiology*; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D017931:DNA Primers; D011994:Recombinant Proteins; D002482:Cellulose; D043364:Endo-1,4-beta Xylanases