Family I7
Summary for family I7
| Name | Inhibitor family I7 (squash family) |
|---|
| Family type peptidase | I07.001 - trypsin inhibitor MCTI-1 (Momordica charantia) (Momordica charantia), MEROPS Accession MER0018077 (inhibitor unit: 1-30) |
| Content of family | Inhibitor family I7 contains serine endopeptidase inhibitors. |
| History |
Identifier created: MEROPS 6.1 (10 January 2003)
The family has grown from the discovery in 1984 of inhibitors in the seeds of two species of cucurbit (Joubert, 1984; Otlewski et al., 1984). |
| Peptidases inhibited | Peptidases inhibited belong to family S1 (Wieczorek et al., 1985). Most of the inhibitors have an arginine P1 reactive site residue, which dictates specificity for peptidases with a trypsin-like substrate preference. |
| Mechanism of inhibition | Inhibitors in family I7 inhibit serine peptidases by the Laskowski mechanism (Otlewski & Zbyryt, 1994). |
| Molecular structure | Inhibitors in family I7 are small proteins of 27-33 amino acid residues cross-linked with three disulfide bridges. Crystal structures are available for two of the inhibitors from Cucurbita maxima (I07.005, I07.008). The fold is described as the 'knottin' fold, and is seen in other groups of proteins also (Heitz et al., 2001). Homologous from the seeds of Momordica cochinchinensis are the only known members of the family that are cyclic and contain an additional loop connecting the N- and C-termini (Avrutina et al., 2005). |
| Clan | IE |
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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 |
details |
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Animals |
details |
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Viruses |
- |
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| Inhibitors and Homologues |
MEROPS ID |
Structure |
| trypsin inhibitor MCTI-1 (Momordica charantia) | I07.001 | Yes |
| elastase inhibitor MCEI (Momordica charantia) | I07.002 | - |
| trypsin inhibitor EETI-II (Ecballium elaterium) | I07.003 | Yes |
| macrocyclic squash trypsin inhibitor (Momordica cochinchinensis) | I07.004 | Yes |
| trypsin inhibitor CMTI-I (Cucurbita maxima) | I07.005 | Yes |
| trypsin inhibitor CPTI (Cucurbita pepo) | I07.006 | Yes |
| trypsin inhibitor CMTI-III (Cucurbita maxima) | I07.007 | - |
| trypsin inhibitor MCTI-II (Momordica charantia) | I07.008 | Yes |
| trypsin inhibitor CVTI-I (Cucurbitaceae) | I07.009 | - |
| trypsin inhibitor TGTI-I (Luffa cylindrica) | I07.010 | - |
| trypsin inhibitor TGTI-II (Luffa cylindrica) | I07.011 | - |
| trypsin inhibitor LCTI (Luffa cylindrica) | I07.012 | - |
| trypsin inhibitor CMTI-II (Cucumis melo) | I07.013 | - |
| trypsin inhibitor CSTI-IIb (Cucumis sativus ) | I07.014 | - |
| trypsin inhibitor CSTI-IV (Cucumis sativus) | I07.015 | - |
| trypsin inhibitor BDTI-II (Bryonia dioica) | I07.016 | - |
| trypsin inhibitor MRTI-I (Momordica repens) | I07.017 | - |
| trypsin inhibitor MCTI-A (Momordica charantia) | I07.018 | Yes |
| trypsin inhibitor CMeTI-B (Cucumis melo) | I07.019 | - |
| trypsin inhibitor TTII (Trichosanthes kirilowii) | I07.020 | - |
| trypsin inhibitor MCTI-III (Momordica charantia) | I07.021 | - |
| Family I07 non-peptidase homologues | non-peptidase homologue | - |
| Family I07 unassigned peptidases | unassigned | - |
