C-type cytochrome-initiated reduction of bacterial lytic polysaccharide monooxygenases

DOI: 10.1042/BCJ20210376

Authors: Jessie Branch (University of Leeds) , Badri S. Rajagopal (University of Essex) , Alessandro Paradisi (University of York) , Nick Yates (University of York) , Peter J Lindley (University of York) , Jake Smith (University of York) , Kristian Hollingsworth (University of Leeds) , Bruce Turnbull (University of Leeds) , Bernard Henrissat (Centre National de la Recherche Scientifique) , Alison Parkin (University of York) , Alan Berry (University of Leeds) , Glyn R. Hemsworth (Structural Biology Laboratory, University of York)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Biochemical Journal

State: Published (Approved)
Published: July 2021
Diamond Proposal Number(s): 15378

Abstract: The release of glucose from lignocellulosic waste for subsequent fermentation into biofuels holds promise for securing humankind's future energy needs. The discovery of a set of copper dependent enzymes known as lytic polysaccharide monooxygenases (LPMOs) has galvanized new research in this area. LPMOs act by oxidatively introducing chain breaks into cellulose and other polysaccharides, boosting the ability of cellulases to act on the substrate. Although several proteins have been implicated as electron sources in fungal LPMO biochemistry, no equivalent bacterial LPMO electron donors have been previously identified, although the proteins Cbp2D and E from Cellvibrio japonicus have been implicated as potential candidates. Here we analyze a small c-type cytochrome (CjX183) present in Cellvibrio japonicus Cbp2D, and show that it caninitiate bacterial CuII/I LPMO reduction and also activate LPMO-catalyzed cellulose-degradation. In the absence of cellulose, CjX183-driven reduction of the LPMO results in less H2O2 production from O2, and correspondingly less oxidative damage to the enzyme than when ascorbate is used as the reducing agent. Significantly, using CjX183 as the activator maintained similar cellulase boosting levels relative to the use of an equivalent amount of ascorbate. Our results therefore add further evidence to the impact that the choice of electron source can have on LPMO action. Furthermore, the study of Cbp2D and other similar proteins may yet reveal new insight into the redox processes governing polysaccharide degradation in bacteria.

Journal Keywords: oxidation-reduction; LPMO; Biofuels; cytochrome; protein structure; electron transfer

Diamond Keywords: Biofuel; Enzymes; Bacteria

Subject Areas: Biology and Bio-materials, Chemistry, Energy


Instruments: I03-Macromolecular Crystallography

Added On: 18/07/2021 10:47

Documents:
bcj-2021-0376.pdf

Discipline Tags:

Bioenergy Earth Sciences & Environment Biotechnology Sustainable Energy Systems Energy Climate Change Biochemistry Chemistry Structural biology Engineering & Technology Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX)