Crystal structures of a dodecameric multicopper oxidase from Marinithermus hydrothermalis

Journal Article · Wed Sep 29 00:00:00 EDT 2021 · Acta Crystallographica. Section D. Structural Biology

DOI:https://doi.org/10.1107/s205979832100944x· OSTI ID:1854592

Paavola, Joseph L.  ^[1]; Battistin, Umberto ^[1]; Ogata, Craig M. ^[2]; Georgiadis, Millie M. ^[1]

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1. Indiana University School of Medicine, Indianapolis IN (United States)
2. Argonne National Laboratory (ANL), Argonne, IL (United States). Advanced Photon Source (APS)

We report multicopper oxidases (MCOs) represent a diverse family of enzymes that catalyze the oxidation of either an organic or a metal substrate with concomitant reduction of dioxygen to water. These enzymes contain variable numbers of cupredoxin domains, two, three or six per subunit, and rely on four copper ions, a single type I copper and three additional copper ions organized in a trinuclear cluster (TNC), with one type II and two type III copper ions, to catalyze the reaction. Here, two crystal structures and the enzymatic characterization of Marinithermus hydrothermalis MCO, a two-domain enzyme, are reported. This enzyme decolorizes Congo Red dye at 70°C in the presence of high halide concentrations and may therefore be useful in the detoxification of industrial waste that contains dyes. In two distinct crystal structures, MhMCO forms the trimers seen in other two-domain MCOs, but differs from these enzymes in that four trimers interact to create a dodecamer. This dodecamer of MhMCO forms a closed ball-like structure and has implications for the sequestration of bound divalent metal ions as well as substrate accessibility. In each subunit of the dodecameric structures, a Trp residue, Trp351, located between the type I and TNC sites exists in two distinct conformations, consistent with a potential role in facilitating electron transfer in the enzyme.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: National Institutes of Health (NIH); National Cancer Institute (NCI); USDOE Office of Science (SC), Basic Energy Sciences (BES); US Department of Education
• Grant/Contract Number: AC02-06CH11357; ACB-12002; AGM-12006; P30GM138396; P015B180101-21
• OSTI ID: 1854592
• Journal Information: Acta Crystallographica. Section D. Structural Biology, Vol. 77, Issue 10; ISSN 2059-7983
• Publisher: IUCr
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
crystal structure
dodecamers
laccases
multi-copper oxidases
thermophiles
Marinithermus hydrothermalis