PAN domains have significant functional versatility fulfilling diverse biological roles by mediating protein-protein and protein-carbohydrate interactions.[1] These domains contain a hair-pin loop like structure, similar to that found in knottins but with a different pattern of disulfide bonds.

PAN_1
solution structure of a pan module from eimeria tenella
Identifiers
SymbolPAN_1
PfamPF00024
Pfam clanCL0168
InterProIPR003014
PROSITEPDOC00376
SCOP21bht / SCOPe / SUPFAM
Available protein structures:
Pfam  structures / ECOD  
PDBRCSB PDB; PDBe; PDBj
PDBsumstructure summary

It has been shown that the N-terminal domains of members of the plasminogen/hepatocyte growth factor family, the apple domains of the plasma prekallikrein/coagulation factor XI family, and domains of various nematode proteins belong to the same module superfamily, the PAN module.[1] The PAN domain contains a conserved core of three disulfide bridges. In some members of the family there is an additional fourth disulfide bridge that links the N- and C-termini of the domain.

The apple domain, as well as other examples of the PAN domain, consists of 7 β-strands that fold into a curved antiparallel sheet cradling an α-helix. Two disulfide bonds lock the helix onto the central β4 and β5 strands, whereas a third connects the N- and C-termini of the domain. In the apple domain, the β4-β5 loop and β5-β6 crossover loop generate a small pocket on the opposite side of the sheet from the α-helix.[2]

In native plasminogen the PAN domain is associated with five kringle domains.[3] The interactions between the PAN domain and the kringles play a critical role in stabilising the quaternary complex of the native plasminogen;

References

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  1. ^ a b Tordai H, Bányai L, Patthy L (November 1999). "The PAN module: the N-terminal domains of plasminogen and hepatocyte growth factor are homologous with the apple domains of the prekallikrein family and with a novel domain found in numerous nematode proteins". FEBS Lett. 461 (1–2): 63–7. Bibcode:1999FEBSL.461...63T. doi:10.1016/s0014-5793(99)01416-7. PMID 10561497. S2CID 29929643.
  2. ^ Emsley J, McEwan PA, Gailani D (Apr 2010). "Structure and function of factor XI". Blood. 115 (13): 2569–77. doi:10.1182/blood-2009-09-199182. PMC 4828079. PMID 20110423.
  3. ^ Xue Y, Bodin C, Olsson K (2012). "Crystal structure of the native plasminogen reveals an activation-resistant compact conformation". J Thromb Haemost. 10 (7): 1385–96. doi:10.1111/j.1538-7836.2012.04765.x. PMID 22540246.
This article incorporates text from the public domain Pfam and InterPro: IPR003014