title: Mapping of residues involved in the interaction between the Bacillus subtilis xylanase A and proteinaceous wheat xylanase inhibitors.
abstract: The Bacillus subtilis xylanase A was subjected to site-directed mutagenesis, aimed at changing the interaction with Triticum aestivum xylanase inhibitor, the only wheat endogenous proteinaceous xylanase inhibitor interacting with this xylanase. The published structure of Bacillus circulans XynA was used to target amino acids surrounding the active site cleft of B.subtilis XynA for mutation. Twenty-two residues were mutated, resulting in 62 different variants. The catalytic activity of active mutants ranged from 563 to 5635 XU/mg and the interaction with T.aestivum xylanase inhibitor showed a similar variation. The results indicate that T.aestivum xylanase inhibitor interacts with several amino acid residues surrounding the active site of the enzyme. Three different amino acid substitutions in one particular residue (D11) completely abolished the interaction between T.aestivum xylanase inhibitor and B.subtilis xylanase A.
authors.affiliation: Danisco, Edwin Rahrs Vej 38, DK-8220 Brabrand and Danisco, Langebrogade 1, DK-1001 Copenhagen C, Denmark. jens.frisbak.sorensen@danisco.com
authors.forename: J F
authors.initials: JF
authors.lastname: Sørensen
authors.forename: O
authors.initials: O
authors.lastname: Sibbesen
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution / Q000235:genetics; D000596:Amino Acids / Q000235:genetics / Q000378:metabolism*; D001412:Bacillus subtilis / Q000201:enzymology*; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D043364:Endo-1,4-beta Xylanases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding / Q000235:genetics; D025941:Protein Interaction Mapping; D014908:Triticum / Q000201:enzymology*
chemical_list: D000596:Amino Acids; D002352:Carrier Proteins; D004791:Enzyme Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D010940:Plant Proteins; C485063:XIP-I protein, Triticum aestivum; D043364:Endo-1,4-beta Xylanases