Abstract
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.
This is a preview of subscription content, log in via an institution to check access.
References
Cunningham C, McPherson CA, Martin J, Harris WJ, Flint HJ (1991) Sequence of a cellulase gene from the rumen anaerobe Ruminococcus flavefaciens 17. Mol Gen Genet 228:320–323
Flint HJ, McPherson CA, Bisset J (1989) Molecular cloning of genes from Ruminococcus flavefaciens encoding xylanase and β(1-3,1-4) glucanase activities. Appl Env Microbiol 55:1230–1233
Flint HJ, McPherson CA, Martin J (1991) Expression of two xylanase genes from the rumen cellulolytic bacterium Ruminococcus flavefaciens cloned in pUC13. J Gen Microbiol 137:123–129
Flint HJ, Martin J, McPherson CA, Daniel AS, Zhang J-X (1993) A bifunctional enzyme having separate xylanase and β(1,3-1,4) glucanase domains, encoded by the xynD gene of Ruminococcus flavefaciens. J Bacteriol 175:2943–2951
Flint HJ, Zhang J-X, Martin J (1994) Multiplicity and expression of xylanases in the rumen cellulolytic bacterium Ruminococcus flavefaciens. Curr Microbiol 29:1–5
Gilkes NR, Henrissat B, Kilburn DG, Miller RC Jr, Warren RAJ (1991) Domains in microbial β-1,4-glycanases: sequence conservation, function and enzyme families. Microbiol Rev 55:303–315
Ogasowara N (1985) Markedly unbiased codon usage in Bacillus subtilis. Gene 40:145–150
Sambrook J, Fritsch EF, Maniatis T (1989) Molecular cloning: a laboratory manual (2nd edn.). Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York
Sanger F, Nicklen S, Coulson AR (1977) DNA sequencing with chain terminating inhibitors. Proc Natl Acad Sci USA 74:5463–5467
Stewart CS, Bryant MP (1988) The rumen bacteria. In: Hudson PN (ed) The rumen microbial ecosystem. Elsevier Applied Science, London-New York, pp 21–75
Tinoco I, Borer PN, Dengler B, Levine MD, Uhlenbeck OC, Crothers DM, Gralla J (1973) Improved estimation of secondary structure in ribonucleic acids. Nature New Biol 246:40–41
von Heijne (1988) Transcending the impenetrable: how proteins come to terms with membranes. Biochim Biophys Acta 947:307–333
Zhang J-X, Flint HJ (1992) A bifunctional xylanase encoded by the xynA gene of the rumen cellulolytic bacterium Ruminococcus flavefaciens comprises two dissimilar catalytic domains linked by an asparagine/glutamine rich sequence. Mol Microbiol 6:1013–1023
Author information
Authors and Affiliations
Additional information
Communicated by J. F. Lengeler
Rights and permissions
About this article
Cite this article
Zhang, JX., Martin, J. & Flint, H.J. Identification of non-catalytic conserved regions in xylanases encoded by the xynB and xynD genes of the cellulolytic rumen anaerobe Ruminococcus flavefaciens . Molec. Gen. Genet. 245, 260–264 (1994). https://doi.org/10.1007/BF00283275
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00283275