title: Two novel GH11 endo-xylanases from Myceliophthora thermophila C1 act differently toward soluble and insoluble xylans.
abstract: Two novel GH11 endo-xylanases from Myceliophthora thermophila C1 (C1), Xyl7 and Xyl8, were purified and the influence of solubility and molecular structure of various xylans on their efficiency was investigated. Both endo-xylanases were hindered by a high degree of substitution of a xylan. The two GH11 xylanases released different products from the xylans, in which Xyl7 displayed a degradation product composition closer to GH10 xylanases. A correlation of the degradation product composition with a specific residue at position 163 in the amino acid sequence of Xyl8 is suggested: tyrosine in Xyl8; valine in Xyl7. This is confirmed with examples of various endo-xylanases reported in literature. The C1 GH11 xylanases were more efficient on self-associated xylan compared to C1 GH10 endo-xylanases and they released more small xylooligomers from these xylans. This is contrary to the general assumption that GH10 xylanases degrade xylans to a higher degree than GH11 xylanases.
authors.affiliation: Laboratory of Food Chemistry, Wageningen University, P.O. Box 8129, 6700 EV Wageningen, The Netherlands.
authors.forename: M P
authors.initials: MP
authors.lastname: van Gool
authors.forename: G C J
authors.initials: GC
authors.lastname: van Muiswinkel
authors.forename: S W A
authors.initials: SW
authors.lastname: Hinz
authors.forename: H A
authors.initials: HA
authors.lastname: Schols
authors.forename: A P
authors.initials: AP
authors.lastname: Sinitsyn
authors.forename: H
authors.initials: H
authors.lastname: Gruppen
mesh_terms: D000595:Amino Acid Sequence; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry / Q000145:classification / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D012995:Solubility; D020037:Sordariales / Q000145:classification / Q000201:enzymology*; D013379:Substrate Specificity; D014990:Xylans / Q000737:chemistry / Q000378:metabolism*
chemical_list: D005656:Fungal Proteins; D014990:Xylans; D043364:Endo-1,4-beta Xylanases