Family M5
Summary for family M5
| Name | Peptidase family M5 (mycolysin family) |
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| Family type peptidase | M05.001 - mycolysin (Streptomyces cacaoi), MEROPS Accession MER0001049 (peptidase unit: 206-550) |
| Content of family | Peptidase family M5 contains a metalloendopeptidase. |
| History |
Identifier created: Biochem.J. 290:205-218 (1993)
Family M5 contains only a peptidase from Streptomyces cacaoi. The gene was cloned and expressed in Streptomyces lividans, and the enzyme named mycolysin (Chang et al., 1990). No homologues are known from any other species, including the completely sequenced Streptomyces coelicolor genome. |
| Catalytic type | Metallo |
| Active site residues | H407 E408 H411 E445 |
| Active site | Like all peptidases in clan MA(E) mycolysin displays the HEXXH motif in which the histidines (His202 and His206) are zinc ligands and the electrophilic Glu203 is a catalytic residue; Glu240 is the third zinc ligand and is found within the Glu-(Xaa)3-Asp motif that is also found in thermolysin. |
| Activities and specificities | Mycolysin is synthesized with a 171-residue propeptide. It is most active in the range pH 5 - 7 (Chang et al., 1990; Chang & Lee, 1992). |
| Inhibitors | Like most metallopeptidases, mycolysin is inhibited by EDTA. |
| Molecular structure | The tertiary structure of mycolysin has not been determined. The primary structure shows no significant similarity to that of any other metallopeptidase. |
| Clan | MA |
| Subclan | MA(E) |
| Basis of clan assignment | Active site residues for members of this family and thermolysin, the type example for clan MA, occur in the motif HEXXH |
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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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Ala bond (Chang et al., 1992). It has an important role in bacterial nutrition.