Summary for clan MM
| History | MEROPS 5.00 (20 Apr 2000) |
| Description | Water nucleophile; water bound by single zinc ion ligated to two His (within the motif HEXXH) and Asp; membrane proteins with intramembrane active site. |
| Contents of clan | Clan MM contains the membrane-embedded metalloendopeptidases of family M50. |
| Evidence | (See Protein fold.) |
| Catalytic mechanism | (See family M50.) |
| Peptidase activity | (See family M50.) |
| Protein fold | The tertiary structure has been determined for the MJ0392 protein (M50.006) from Methanocaldococcus jannaschii (Feng et al., 2007). Two of the metal ligands occur in an HEXXH motif, similar to that found in clan MA, and the third is an Asp. The active site is within one of the six transmembrane regions, and the fold is unlike that of thermolysin (M04.001), the type example for clan MA. Consequently, family M50 is placed in its own clan, MM. |
| Evolution | The presence of homologues of clan MM in the genomes of bacteria, archaea and eukaryotes suggests that the clan is a very ancient one (Kinch & Grishin, 2005). |
| Activation mechanism | The activity of SpoIVFB (M50.002) is regulated by two other integral membrane proteins, SpoIVFA and BofA (Rudner & Losick, 2002). |
Families
| M50 |
site 2 peptidase (Homo sapiens) |
Yes |
Distribution of clan MM among Kingdoms of Organisms
