The crystal structure of methanol dehydrogenase, a quinoprotein from the marine methylotrophic bacterium Methylophaga aminisulfidivorans MP T

Thinh Phat Cao, Jin Myung Choi, Si Wouk Kim, Sung Haeng Lee

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The first crystal structure of a pyrroloquinoline quinone (PQQ)-dependent methanol dehydrogenase (MDH) from a marine methylotrophic bacterium, Methylophaga aminisulfidivorans MP T (MDH Mas ), was determined at 1.7 Å resolution. The active form of MDH Mas (or MDHI Mas ) is a heterotetrameric α 2 β 2 , where each β-subunit assembles on one side of each of the α-subunits, in a symmetrical fashion, so that two β-subunits surround the two PQQ-binding pockets on the α-subunits. The active site consists of a PQQ molecule surrounded by a β-propeller fold for each α-subunit. Interestingly, the PQQ molecules are coordinated by a Mg 2+ ion, instead of the Ca 2+ ion that is commonly found in the terrestrial MDHI, indicating the efficiency of osmotic balance regulation in the high salt environment. The overall interaction of the β-subunits with the α-subunits appears tighter than that of terrestrial homologues, suggesting the efficient maintenance of MDHI Mas integrity in the sea water environment to provide a firm basis for complex formation with MxaJ Mas or Cyt c L . With the help of the features mentioned above, our research may enable the elucidation of the full molecular mechanism of methanol oxidation by taking advantage of marine bacterium-originated proteins in the methanol oxidizing system (mox), including MxaJ, as the attainment of these proteins from terrestrial bacteria for structural studies has not been successful.

Original languageEnglish
Pages (from-to)246-254
Number of pages9
JournalThe Journal of Microbiology
Issue number4
Publication statusPublished - 1 Apr 2018
Externally publishedYes


  • marine bacterium
  • methanol dehydrogenase
  • methanol oxidizing system
  • Mg
  • pyrroloquinoline quinone

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