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87  structures 2599  species 7  interactions 22094  sequences 614  architectures

Clan: PPP-I (CL0570)


Protease propeptides/inhibitors Add an annotation

This superfamily is characterised by families of short N-terminal domains such as the pancreatic carboxypeptidase activation domain, the subtilase propeptides/inhibitors, the prohormone convertase 1 pro-domain, and the peptidase- S8 pro-domain. All families exbhibit an alpha+beta sandwich with antiparallel beta-sheets in a (beta-alpha-beta)x2 conformation.

This clan contains 6 families and the total number of domains in the clan is 22094. The clan was built by P Coggill.


This clan contains the following 6 member families:

Inhibitor_I9 Pro-kuma_activ Pro_sub2 Propep_M14 S8_pro-domain Tk-SP_N-pro

External database links

Domain organisation

Below is a listing of the unique domain organisations or architectures from this clan. More...

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The table below shows the number of occurrences of each domain throughout the sequence database. More...

Pfam family Num. domains Alignment
Inhibitor_I9 (PF05922) 12642 (57.2%) View
Pro-kuma_activ (PF09286) 4396 (19.9%) View
Propep_M14 (PF02244) 2906 (13.2%) View
S8_pro-domain (PF16470) 2126 (9.6%) View
Tk-SP_N-pro (PF18237) 19 (0.1%) View
Pro_sub2 (PF18513) 5 (0.0%) View
Total: 6 Total: 22094 Clan alignment

Please note: Clan alignments can be very large and can cause problems for some browsers. Read the note above before viewing.

Family relationships

This diagram shows the relationships between members of this clan. More...

Species distribution

Tree controls


This tree shows the occurrence of the domains in this clan across different species. More...



There are 7 interactions for this clan. More...

Interacting families
Inhibitor_I9 Ldl_recept_b
Peptidase_M14 Propep_M14
Peptidase_S8 Inhibitor_I9
Pro-kuma_activ Peptidase_S8
Propep_M14 Peptidase_M14


For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the MSD group, to allow us to map Pfam domains onto UniProt three-dimensional structures. The table below shows the mapping between the Pfam families in this clan, the corresponding UniProt entries, and the region of the three-dimensional structures that are available for that sequence.

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