Identification of non-catalytic conserved regions in xylanases encoded by the xynB and xynD genes of the cellulolytic rumen anaerobe Ruminococcus flavefaciens

J X Zhang, J Martin, Harry James Flint, Jennifer Cynthia Martin

Research output: Contribution to journalArticle

28 Citations (Scopus)


xynB is one of at least four genes from the cellulolytic rumen anaerobe Ruminococcus flavefaciens 17 that encode xylanase activity. The xynB gene is predicted to encode a 781-amino acid product starting with a signal peptide, followed by an amino-terminal xylanase domain which is identical at 89% and 78% of residues, respectively, to the amino-terminal xylanase domains of the bifunctional XynD and XynA enzymes from the same organism. Two separate regions within the carboxy-terminal 537 amino acids of XynB also show close similarities with domain B of XynD. These regions show no significant homology with cellulose- or xylan-binding domains from other species, or with any other sequences, and their functions are unknown. In addition a 30 to 32-residue threonine-rich region is present in both XynD and XynB. Codon usage shows a consistent pattern of bias in the three xylanase genes from R. flavefaciens that have been sequenced.

Original languageEnglish
Pages (from-to)260-4
Number of pages5
JournalMolecular & general genetics
Issue number2
Publication statusPublished - 28 Oct 1994



  • Amino Acid Sequence
  • Animals
  • Bacillus subtilis
  • Bacteria, Anaerobic
  • Bacterial Proteins
  • Base Sequence
  • Escherichia coli
  • Genes, Bacterial
  • Gram-Positive Cocci
  • Molecular Sequence Data
  • Rumen
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Species Specificity
  • Xylan Endo-1,3-beta-Xylosidase
  • Xylosidases

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