The netrin (NTR) module is an about 130-residue domain found in the C-terminal parts of netrins, complement proteins C3, C4, and C5, secreted frizzled-related proteins, and type I procollagen C-proteinase enhancer proteins (PCOLCEs), as well as in the N-terminal parts of tissue inhibitors of metalloproteinases (TIMPs) (see <PDOC00260>). The proteins harboring the NTR domain fulfill diverse biological roles ranging from axon guidance, regulation of Wnt signalling, to the control of the activity of metalloproteinases. The NTR domain can be found associated to other domains such as CUB (see <PDOC00908>), WAP (see <PDOC00026>), Kazal (see <PDOC00254>), Kunitz (see <PDOC00252>), Ig-like (see <PDOC50835>), laminin N-terminal, laminin-type EGF (see <PDOC00961>) or frizzled (see <PDOC50038>). The NTR domain is implicated in inhibition of zinc metalloproteinases of the metzincin family [1,2].

The NTR module is a basic domain containing six conserved cysteines, which are likely to form internal disulfide bonds, and several conserved blocks of hydrophobic residues (including an YLLLG-like motif). The NTR module consists of a β-barrel with two terminal α-helices packed side by side against the face of the β-barrel (see <PDB:1BR9>) [1].

The profile we developed covers the entire NTR domain.