PCuAC domains from methane-oxidizing bacteria use a histidine brace to bind copper
Year: 2019
Type: article
Abstract: Copper is critically important for methanotrophic bacteria because their primary metabolic enzyme, particulate methane monooxygenase (pMMO), is copper-dependent. In addition to pMMO, many other copper proteins are encoded in the genomes of methanotrophs, including proteins that contain periplasmic copper-A chaperone (PCu A C) domains. Using bioinformatics analyses, we identified three distinct classes of PCu A C domain-containing proteins in methanotrophs, termed PmoF1, PmoF2, and PmoF3. PCu A C domains from other types of bacteria bind a single Cu(I) ion via an H X n M X 21/22 H X M motif, which is also present in PmoF3, but PmoF1 and PmoF2 lack this motif entirely. Instead, the PCu A C domains of PmoF1 and PmoF2 bind only Cu(II), and PmoF1 binds additional Cu(II) ions in a His-rich extension to its PCu A C domain. Crystal structures of the PmoF1 and PmoF2 PCu A C domains reveal that Cu(II) is coordinated by an N-terminal histidine brace H X 10 H motif. This binding site is distinct from those of previously characterized PCu A C domains but resembles copper centers in CopC proteins and lytic polysaccharide monooxygenase (LPMO) enzymes. Bioinformatics analysis of the entire PCu A C family reveals previously unappreciated diversity, including sequences that contain both the H X n M X 21/22 H X M and H X 10 H motifs, and sequences that lack either set of copper-binding ligands. These findings provide the first characterization of an additional class of copper proteins from methanotrophs, further expand the PCu A C family, and afford new insight into the biological significance of histidine brace-mediated copper coordination.
Source: Journal of Biological Chemistry
Authors: Oriana S. Fisher, Madison R. Sendzik, Matthew O. Ross, Thomas J. Lawton, Brian M. Hoffman, Amy C. Rosenzweig
Institution: Northwestern University
Language: English
Subfield: Inorganic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,430
Awards: G109972301, G114462934, MISSING LINKS IN BIOLOGICAL METHANE AND AMMONIA OXIDATION, Characterization of pmoD, G4082334743, G4744707546, G4764642483, G6969342140, G839251883, INSTITUTE FOR PROTEOMICS AND NANOBIOTECHNOLOGY AT NORTHWESTERN UNIVERSITY IN EVANSTON, IL, G8959508869, G9000243610, Biological Transition Metals
OpenAlex ID: W2974656599