4QI6

Cellobiose dehydrogenase from Myriococcum thermophilum, MtCDH

Summary for 4QI6

• Entry DOI: 10.2210/pdb4qi6/pdb
• Related: 4QI3 4QI4 4QI5 4QI7 4QI8
• Descriptor: Cellobiose dehydrogenase, PROTOPORPHYRIN IX CONTAINING FE, FLAVIN-ADENINE DINUCLEOTIDE, ... (5 entities in total)
• Functional Keywords: immunoglobulin-like beta-sandwich (cytochrome), fad/nad(p)-binding domain (dehydrogenase domain), cellobiose oxidizing, electron transfer, lignocellulose degradation, cellobiose, lpmo, oxidoreductase
• Biological source: Myriococcum thermophilum
• Total number of polymer chains: 1
• Total formula weight: 89858.48

Authors

Tan, T.C.,Gandini, R.,Sygmund, C.,Kittl, R.,Haltrich, D.,Ludwig, R.,Hallberg, B.M.,Divne, C. (deposition date: 2014-05-30, release date: 2015-07-15, Last modification date: 2024-10-09)

Primary citation

Tan, T.C.,Kracher, D.,Gandini, R.,Sygmund, C.,Kittl, R.,Haltrich, D.,Hallberg, B.M.,Ludwig, R.,Divne, C.
Structural basis for cellobiose dehydrogenase action during oxidative cellulose degradation.
Nat Commun, 6:7542-7542, 2015

PubMed Abstract: 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.

PubMed: 26151670
DOI: 10.1038/ncomms8542

Experimental method

X-RAY DIFFRACTION (3.2 Å)