Falcon deep research report for mxaG (cytochrome c_L) in Methylorubrum extorquens AM1
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MxaG (cytochrome c_L) is the cognate periplasmic electron acceptor for methylotrophic PQQ-dependent methanol/alcohol dehydrogenases, transferring electrons from PQQ to additional cytochromes in the respiratory electron transport chain.
"All methylotrophic PQQ-ADHs are periplasmic enzymes associated with a cytochrome cL (MxaG, XoxG, and ExaG, respectively) that transfers electrons from PQQ to additional cytochromes in the electron transport chain"
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The mxa methanol-oxidation gene cluster encodes the specific cytochrome c that accepts electrons from methanol dehydrogenase.
"the specific cytochrome c that accepts electrons from methanol dehydrogenase"
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Mechanistically, reduced PQQ is reoxidized by transferring electrons to the heme of cytochrome c_L, which is in turn oxidized by downstream cytochromes.
"reduced PQQ is reoxidized by transferring electrons to the heme of cytochrome cL, which is then oxidized by downstream cytochromes"
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MxaG is a shuttle, not a catalyst - it does not itself catalyze methanol oxidation but mediates electron transfer from the MDH redox cofactor PQQ to downstream respiratory components.
"MxaG itself does not catalyze methanol oxidation; rather, it"
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Methanol oxidation by the PQQ-dependent dehydrogenases, and hence the cytochrome c_L electron-transfer step it feeds, occurs in the periplasm.
"methanol oxidation occurs in the periplasm via PQQ-dependent ADHs"
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Electron flow proceeds from PQQ to cytochrome c_L and onward to additional cytochromes/respiratory chain components, coupling methanol oxidation to energy generation.
"Electrons are transferred from PQQ to cytochrome cL and then to additional cytochromes/respiratory chain components, coupling methanol oxidation to energy generation"