Sie können Bookmarks mittels Listen verwalten, loggen Sie sich dafür bitte in Ihr SLUB Benutzerkonto ein.
Medientyp:
E-Artikel
Titel:
Structural basis for cellobiose dehydrogenase action during oxidative cellulose degradation
Beteiligte:
Tan, Tien-Chye;
Kracher, Daniel;
Gandini, Rosaria;
Sygmund, Christoph;
Kittl, Roman;
Haltrich, Dietmar;
Hällberg, B. Martin;
Ludwig, Roland;
Divne, Christina
Erschienen:
Springer Science and Business Media LLC, 2015
Erschienen in:Nature Communications
Sprache:
Englisch
DOI:
10.1038/ncomms8542
ISSN:
2041-1723
Entstehung:
Anmerkungen:
Beschreibung:
<jats:title>Abstract</jats:title><jats:p>A new paradigm for cellulose depolymerization by fungi focuses on an oxidative mechanism involving cellobiose dehydrogenases (CDH) and copper-dependent lytic polysaccharide monooxygenases (LPMO); however, mechanistic studies have been hampered by the lack of structural information regarding CDH. CDH contains a haem-binding cytochrome (CYT) connected via a flexible linker to a flavin-dependent dehydrogenase (DH). Electrons are generated from cellobiose oxidation catalysed by DH and shuttled via CYT to LPMO. Here we present structural analyses that provide a comprehensive picture of CDH conformers, which govern the electron transfer between redox centres. Using structure-based site-directed mutagenesis, rapid kinetics analysis and molecular docking, we demonstrate that flavin-to-haem interdomain electron transfer (IET) is enabled by a haem propionate group and that rapid IET requires a closed CDH state in which the propionate is tightly enfolded by DH. Following haem reduction, CYT reduces LPMO to initiate oxygen activation at the copper centre and subsequent cellulose depolymerization.</jats:p>