title: The putative endoglucanase PcGH61D from Phanerochaete chrysosporium is a metal-dependent oxidative enzyme that cleaves cellulose.
abstract: Many fungi growing on plant biomass produce proteins currently classified as glycoside hydrolase family 61 (GH61), some of which are known to act synergistically with cellulases. In this study we show that PcGH61D, the gene product of an open reading frame in the genome of Phanerochaete chrysosporium, is an enzyme that cleaves cellulose using a metal-dependent oxidative mechanism that leads to generation of aldonic acids. The activity of this enzyme and its beneficial effect on the efficiency of classical cellulases are stimulated by the presence of electron donors. Experiments with reduced cellulose confirmed the oxidative nature of the reaction catalyzed by PcGH61D and indicated that the enzyme may be capable of penetrating into the substrate. Considering the abundance of GH61-encoding genes in fungi and genes encoding their functional bacterial homologues currently classified as carbohydrate binding modules family 33 (CBM33), this enzyme activity is likely to turn out as a major determinant of microbial biomass-degrading efficiency.
authors: Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway.
authors: Bjørge
authors: B
authors: Westereng
authors: Takuya
authors: T
authors: Ishida
authors: Gustav
authors: G
authors: Vaaje-Kolstad
authors: Miao
authors: M
authors: Wu
authors: Vincent G H
authors: VG
authors: Eijsink
authors: Kiyohiko
authors: K
authors: Igarashi
authors: Masahiro
authors: M
authors: Samejima
authors: Jerry
authors: J
authors: Ståhlberg
authors: Svein J
authors: SJ
authors: Horn
authors: Mats
authors: M
authors: Sandgren
mesh_terms: D000595:Amino Acid Sequence; D002480:Cellulase / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D002482:Cellulose / Q000378:metabolism*; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D007477:Ions; D008670:Metals / Q000494:pharmacology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction / Q000187:drug effects; D020075:Phanerochaete / Q000187:drug effects / Q000201:enzymology*; D011994:Recombinant Proteins / Q000378:metabolism; D019163:Reducing Agents / Q000494:pharmacology; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D040681:Structural Homology, Protein; D013379:Substrate Specificity / Q000187:drug effects
chemical_list: D007477:Ions; D008670:Metals; D011994:Recombinant Proteins; D019163:Reducing Agents; D002482:Cellulose; D002480:Cellulase