HMM Summary Page: TIGR03870

Functionmethanol oxidation system protein MoxJ
Gene SymbolmoxJ
Trusted Cutoff258.10
Domain Trusted Cutoff258.10
Noise Cutoff164.60
Domain Noise Cutoff164.60
Isology Typeequivalog
HMM Length246
Mainrole CategoryTransport and binding proteins
Subrole CategoryCarbohydrates, organic alcohols, and acids
Gene Ontology TermGO:0005215: transporter activity molecular_function
GO:0042597: periplasmic space cellular_component
GO:0046170: methanol catabolic process biological_process
AuthorHaft DH
Entry DateOct 15 2009 4:19PM
Last ModifiedFeb 14 2011 3:27PM
CommentThis predicted periplasmic protein, called MoxJ or MxaJ, is required for methanol oxidation in Methylobacterium extorquens. Two differing lines of evidence suggest two different roles. Forming one view, homology suggests it is the substrate-binding protein of an ABC transporter associated with methanol oxidation. The gene, furthermore, is found regular in genomes with, and only two or three genes away from, a corresponding permease and ATP-binding cassette gene pair. The other view is that this protein is an accessory factor or additional subunit of methanol dehydrogenase itself. Mutational studies show a dependence on this protein for expression of the PQQ-dependent, two-subunit methanol dehydrogenase (MxaF and MxaI) in Methylobacterium extorquens, as if it is a chaperone for enzyme assembly or a third subunit. A homologous N-terminal sequence was found in Paracoccus denitrificans as a 32Kd third subunit. This protein may, in fact, be both, a component of a periplasmic enzyme that converts methanol to formaldehyde and a component of an ABC transporter that delivers the resulting formaldehyde to the cell's interior.