The domain within your query sequence starts at position 380 and ends at position 463; the E-value for the CT domain shown below is 3.6e-35.



C-terminal cystine knot-like domain (CTCK)
SMART accession number:SM00041
Description: The structures of transforming growth factor-beta (TGFbeta), nerve growth factor (NGF), platelet-derived growth factor (PDGF) and gonadotropin all form 2 highly twisted antiparallel pairs of beta-strands and contain three disulphide bonds. The domain is non-globular and little is conserved among these presumed homologues except for their cysteine residues. CT domains are predicted to form homodimers.
Interpro abstract (IPR006207):

Four recent crystal structures of growth factors--nerve growth factor, transforming growth factor-beta, platelet-derived growth factor, and human chorionic gonadotropin--from four separate superfamilies revealed that these proteins are structurally related and share a common overall topology [ (PUBMED:8490958) ]. These proteins have very little sequence homology, but they all have an unusual arrangement of six cysteines linked to form a "cystine-knot" conformation. The active forms of these proteins are dimers, either homo- or heterodimers [ (PUBMED:7663117) ]. Because of their shape, there appears to be an intrinsic requirement for the cystine-knot growth factors to form dimers. This extra level of organisation increases the variety of structures built around this simple structural motif [ (PUBMED:7583638) ].

Family alignment:
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There are 7744 CT domains in 7736 proteins in SMART's nrdb database.

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