Domain

Peptidase M41, FtsH extracellular (IPR011546)

Short name: Pept_M41_FtsH_extracell

Domain relationships

None.

Description

Over 70 metallopeptidase families have been identified to date. In these enzymes a divalent cation which is usually zinc, but may be cobalt, manganese or copper, activates the water molecule. The metal ion is held in place by amino acid ligands, usually three in number. In some families of co-catalytic metallopeptidases, two metal ions are observed in crystal structures ligated by five amino acids, with one amino acid ligating both metal ions. The known metal ligands are His, Glu, Asp or Lys. At least one other residue is required for catalysis, which may play an electrophillic role. Many metalloproteases contain an HEXXH motif, which has been shown in crystallographic studies to form part of the metal-binding site [PMID: 7674922]. The HEXXH motif is relatively common, but can be more stringently defined for metalloproteases as 'abXHEbbHbc', where 'a' is most often valine or threonine and forms part of the S1' subsite in thermolysin and neprilysin, 'b' is an uncharged residue, and 'c' a hydrophobic residue. Proline is never found in this site, possibly because it would break the helical structure adopted by this motif in metalloproteases [PMID: 7674922].

This domain is found in the FtsH family of proteins that include FtsH a membrane-bound ATP-dependent protease universally conserved in prokaryotes [PMID: 12732516]. The FtsH peptidases, which belong to MEROPS peptidase family M41 (clan MA(E)), efficiently degrade proteins that have a low thermodynamic stability - e.g. they lack robust unfoldase activity. This feature may be key and implies that this could be a criterion for degrading a protein. In Oenococcus oeni (Leuconostoc oenos) FtsH is involved in protection against environmental stress [PMID: 12667449], and shows increased expression under heat or osmotic stress. These two lines of evidence suggest that it is a fundamental prokaryotic self-protection mechanism that checks if proteins are correctly folded. The precise function of this N-terminal region is unclear.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0005524 ATP binding
GO:0004222 metalloendopeptidase activity
GO:0008270 zinc ion binding

Cellular Component

GO:0016021 integral component of membrane

Contributing signatures

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