Family M44
Summary for family M44
| Family type peptidase | M44.001 - pox virus metallopeptidase (Vaccinia virus), MEROPS Accession MER0002122 (peptidase unit: 1-591) |
| Content of family | Peptidase family M44 contains a metalloendopeptidase from the pox viruses. |
| History |
Identifier created: Proteolysis in Cell Function, pp13-21, IOS Press, Amsterdam (1997)
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| Catalytic type | Metallo |
| Active site residues | H41 E44 H45 E112 |
| Active site | Family M44 members contain three zinc-binding ligands and a catalytic glutamate. The first two zinc ligands are histidine residues, found together with the catalytic glutamate in a HXXEH motif, an inverse of the classical metallopeptidase motif, HEXXH. The third zinc ligand is a glutamate C-terminal to the HXXEH motif within a motif ELENEY (see the Alignment). |
| Activities and specificities | The vaccinia virus metalloendopeptidase (M44.001) processes the viral polyprotein into multiple fragments at Ala-Gly Xaa motifs where Xaa is Ala, Ser, Thr or Lys (Byrd et al., 2004). The enzyme is inactivated by mutations in the HXXEH motif. |
| Molecular structure | It is predicted that vaccinia virus metalloendopeptidase is structurally similar to mitochondrial processing peptidase (M16.003). Therefore, the family M44 is included in clan ME (Hedengren-Olcott et al., 2004). |
| Clan | ME |
| Basis of clan assignment | Active site residues for members of this family and family M16 occur in the motif HXXEH |
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Distribution of family
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Bacteria |
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Archaea |
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Protozoa |
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Fungi |
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Plants |
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Animals |
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Viruses |
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