Alkylmercury lyase (IPR004927)

Short name: MerB

Overlapping homologous superfamilies


Family relationships



Mercury is a highly toxic metal. Toxicity can result from three different mercurial forms: elemental, inorganic ion and organomercurial compounds. The ability of bacteria to detoxify mercurial compounds by reduction and volatilisation is conferred by the Mer genes, which are usually plasmid encoded (although chromosome resistance determinants have also occasionally been identified) [PMID: 9168120]. Organomercurial lyase (MerB), also known as alkylmercury lyase, mediates the first of the two steps in the microbial detoxification of organomercurial salts (the other catalysed by mercuric reductase).

Organomercurial lyase catalyses the protonolysis of the C-Hg bond in a wide range of organomercurial salts (primary, secondary, tertiary, alkyl, vinyl, allyl and aryl) to Hg(II) and the respective organic compound [PMID: 10548738]:

RHg(+) + H(+) = RH + Hg(2+)

Hg(II) is subsequently detoxified by mercuric reductase.

The enzyme has been purified to homogeneity in Escherichia coli and has been found to be a 22.4kDa monomer with no detectable cofactors or metal ions.

GO terms

Biological Process

GO:0046413 organomercury catabolic process

Molecular Function

GO:0018836 alkylmercury lyase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.