NOVELTY - An isolated Coniothyrium minitans nucleic acid molecule (cxy1), which encodes a polypeptide (Cxy1) having xylanolytic activity, is new.    USE - The cxy1 nucleic acid molecule is compatible with both eukaryotic and prokaryotic expression systems, making it particularly useful for a wide range of industrial applications, e.g. improvement of nutritional availability of carbohydrates in animal feeds. The xylanase enzyme, Cxy1, is useful for the enzymatic removal of xylan from woody plant tissue to improve pulp quality. It is also useful for degrading agricultural wastes to reduce organic waste disposal in landfill sites. Xylanase is also useful for improving the quality of flour in baked goods. Because xylan represents considerable reserve of nutritive sugar sequestered in plant biomass, xylanase is important in ruminal digestion of forage fiber, where the release of xylose monomers may provide a nutritive source for non-xylanolytic ruminal microflora.    DETAILED DESCRIPTION - The encoded Cxy1 has an amino acid sequence comprising:    (a) a fully defined 384 amino acid sequence (Cxy1-I) given in the specification, or a functional equivalent having at least 85% homology to Cxy1-I;    (b) amino acids 84-384 (Cxy1-Ib) of Cxy1-I, or a functional equivalent having at least 85% homology to Cxy1-Ib; (c)    (c) amino acids 22-384 (Cxy1-Ic) of Cxy1-I, or a functional equivalent having at least 85% homology to Cxy1-Ic; or    (d) amino acids 22-83 (Cxy1-Id) of Cxy1-I, or a functional equivalent having at least 85% homology to Cxy1-Id.    INDEPENDENT CLAIMS are also included for the following:    (1) a nucleic acid construct comprising the nucleic acid molecule encoding Cxy1-Id, which encodes a catalytic domain of a hemicellulose-degrading enzyme and which is heterologous to Cxy1-Id;    (2) a vector comprising cxy1;    (3) a cell other than C. minitans comprising cxy1; and    (4) a method for producing a polypeptide having xylanolytic activity comprising:    (a) culturing a cell comprising cxy1 to express the polypeptide Cxy1; and    (b) recovering the encoded Cxy1.