Skip to main content

Function

Catalyzes the oxidation of methanethiol, an organosulfur compound known to be produced in substantial amounts by gut bacteria (PubMed:29255262). Selenium-binding protein which may be involved in the sensing of reactive xenobiotics in the cytoplasm. May be involved in intra-Golgi protein transport (By similarity).

Involvement in disease

Extraoral halitosis due to methanethiol oxidase deficiency

EHMTO

An autosomal recessive malodor condition characterized by extraoral blood-borne halitosis resulting from the accumulation of sulfur-containing metabolites. In extraoral blood-borne halitosis, malodorant compounds are carried to the lungs, where they enter the breath. Affected individuals have a cabbage-like breath odor, high levels of methanethiol and dimethylsulfide in oral and nasal breath, and elevated urinary excretion of dimethylsulfoxide in the absence of intake of dimethylsulfide-containing food or use of sulfur-containing medication, lower-gastrointestinal problems, and known metabolic defects, such as methionine adenosyltransferase deficiency and tyrosinemia.

None

The disease is caused by variants affecting the gene represented in this entry.

Pathway

Organosulfur degradation.

Post-translational modifications

Phosphorylated.

The N-terminus is blocked.

Sequence similarities

Belongs to the selenium-binding protein family.

Tissue specificity

Widely expressed. Highly expressed in liver, lung, colon, prostate, kidney and pancreas. In brain, present both in neurons and glia (at protein level). Down-regulated in lung adenocarcinoma, colorectal carcinoma and ovarian cancer. Two-fold up-regulated in brain and blood from schizophrenia patients.

Cellular localization

  • Nucleus
  • Cytoplasm
  • Cytosol
  • Membrane
  • Peripheral membrane protein
  • May associate with Golgi membrane (By similarity). May associate with the membrane of autophagosomes (By similarity).

Alternative names

SBP, SELENBP1, Methanethiol oxidase, MTO, 56 kDa selenium-binding protein, Selenium-binding protein 1, SBP56, SP56

Target type

Proteins

Primary research area

Oncology

Molecular weight

52391Da