Hg(II)-responsive transcriptional regulator (IPR011794)

Short name: MerR

Overlapping homologous superfamilies

Family relationships



This entry represents the mercury (II) responsive transcriptional activator of the mer organomercurial resistance operon [PMID: 2492496]. This protein is a member of the MerR family of transcriptional activators and contains a distinctive pattern of cysteine residues in its metal binding loop, Cys-X(8)-Cys-Pro, as well as a conserved and critical cysteine at the N-terminal end of the dimerization helix [PMID: 12958362].

MerR1 transcription regulators, such as Tn21 MerR and Tn501 MerR, mediate response to mercury exposure in eubacteria [PMID: 12829265]. These proteins are comprised of distinct domains that harbour the regulatory (effector-binding) site and the active (DNA-binding) site. Their conserved N-terminal domains contain winged HTH motifs that mediate DNA binding, while the C-terminal domains have three conserved cysteines that define a mercury binding site [PMID: 2305262, PMID: 9843394, PMID: 16514151]. These proteins share the N-terminal DNA binding domain with other transcription regulators of the MerR superfamily that promote transcription by reconfiguring the spacer between the -35 and -10 promoter elements [PMID: 10079080].

GO terms

Biological Process

GO:0006355 regulation of transcription, DNA-templated
GO:0046689 response to mercury ion

Molecular Function

GO:0003677 DNA binding
GO:0045340 mercury ion binding

Cellular Component

No terms assigned in this category.

Contributing signatures

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