title: The xynC gene from Fibrobacter succinogenes S85 codes for a xylanase with two similar catalytic domains.
abstract: The xynC gene of Fibrobacter succinogenes S85 codes for a 66.4-kDa xylanase which consists of three distinct domains separated by two flexible regions rich in serine residues. Domains A and B of XynC code for catalytic domains with 56.5% identity and 9.6% similarity with each other, and both domains share homology with xylanases of Ruminococcus flavefaciens, Neocallimastix patriciarum, Clostridium acetobutylicum, Bacillus pumilus, Bacillus subtilis, and Bacillus circulans. More than 88% of the xylanase activity of Escherichia coli cells carrying the original 13-kb recombinant plasmid was released from intact cells by cold water washes. The major products of hydrolysis of xylan by both domains were xylose and xylobiose, indicating that the xynC gene product exhibits catalytic properties similar to those of the XynA xylanases from R. flavefaciens and N. patriciarum. So far, these features are not shared broadly with bacteria from other environments and may indicate specific selection for this domain structure in the highly competitive environment of the rumen.
authors.affiliation: Department of Microbiology, University of Guelph, Ontario, Canada.
authors.forename: F W
authors.initials: FW
authors.lastname: Paradis
authors.forename: H
authors.initials: H
authors.lastname: Zhu
authors.forename: P J
authors.initials: PJ
authors.lastname: Krell
authors.forename: J P
authors.initials: JP
authors.lastname: Phillips
authors.forename: C W
authors.initials: CW
authors.lastname: Forsberg
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D002384:Catalysis; D003001:Cloning, Molecular; D004252:DNA Mutational Analysis; D004926:Escherichia coli / Q000235:genetics; D006026:Glycoside Hydrolases / Q000235:genetics*; D006089:Gram-Negative Anaerobic Bacteria / Q000201:enzymology* / Q000235:genetics*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D011401:Promoter Regions, Genetic / Q000235:genetics; D011994:Recombinant Proteins / Q000096:biosynthesis; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D043325:Xylan Endo-1,3-beta-Xylosidase
chemical_list: D011994:Recombinant Proteins; D006026:Glycoside Hydrolases; D043325:Xylan Endo-1,3-beta-Xylosidase