Structure and function of the lanthanide-dependent methanol dehydrogenase XoxF from the methanotroph Methylomicrobium buryatense 5GB1C.
J Biol Inorg Chem
; 23(7): 1037-1047, 2018 10.
Article
em En
| MEDLINE
| ID: mdl-30132076
ABSTRACT
In methylotrophic bacteria, which use one-carbon (C1) compounds as a carbon source, methanol is oxidized by pyrroloquinoline quinone (PQQ)-dependent methanol dehydrogenase (MDH) enzymes. Methylotrophic genomes generally encode two distinct MDHs, MxaF and XoxF. MxaF is a well-studied, calcium-dependent heterotetrameric enzyme whereas XoxF is a lanthanide-dependent homodimer. Recent studies suggest that XoxFs are likely the functional MDHs in many environments. In methanotrophs, methylotrophs that utilize methane, interactions between particulate methane monooxygenase (pMMO) and MxaF have been detected. To investigate the possibility of interactions between pMMO and XoxF, XoxF was isolated from the methanotroph Methylomicrobium buryatense 5GB1C (5G-XoxF). Purified 5G-XoxF exhibits a specific activity of 0.16 µmol DCPIP reduced min-1 mg-1. The 1.85 Å resolution crystal structure reveals a La(III) ion in the active site, in contrast to the calcium ion in MxaF. The overall fold is similar to other MDH structures, but 5G-XoxF is a monomer in solution. An interaction between 5G-XoxF and its cognate pMMO was detected by biolayer interferometry, with a KD value of 50 ± 17 µM. These results suggest an alternative model of MDH-pMMO association, in which a XoxF monomer may bind to pMMO, and underscore the potential importance of lanthanide-dependent MDHs in biological methane oxidation.
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Base de dados:
MEDLINE
Assunto principal:
Methylococcaceae
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Elementos da Série dos Lantanídeos
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Oxirredutases do Álcool
Idioma:
En
Revista:
J Biol Inorg Chem
Assunto da revista:
BIOQUIMICA
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Estados Unidos