Cystine knot, C-terminal (IPR006207)

Short name: Cys_knot_C

Overlapping homologous superfamilies


Domain relationships



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 [PMID: 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 [PMID: 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 [PMID: 7583638].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE patterns
PROSITE profiles