The domain within your query sequence starts at position 21 and ends at position 93; the E-value for the PDGF_N domain shown below is 1.1e-21.

EGDPIPEELYEMLSDHSIRSFDDLQRLLHRDSVDEDGAELDLNMTRAHSGVELESSSRGR
RSLGSLAAAEPAV

PDGF_N

PDGF_N
PFAM accession number:PF04692
Interpro abstract (IPR006782):

Platelet-derived growth factor (PDGF) [ (PUBMED:2546599) (PUBMED:1425569) ] is a potent mitogen for cells of mesenchymal origin, including smooth muscle cells and glial cells. In both mouse and human, the PDGF signalling network consists of four ligands, PDGFA-D, and two receptors, PDGFRalpha and PDGFRbeta. All PDGFs function as secreted, disulphide-linked homodimers, but only PDGFA and B can form functional heterodimers. PDGFRs also function as homo- and heterodimers. All known PDGFs have characteristic `PDGF domains', which include eight conserved cysteines that are involved in inter- and intramolecular bonds. Alternate splicing of the A chain transcript can give rise to two different forms that differ only in their C-terminal extremity. The transforming protein of Woolly monkey sarcoma virus (WMSV) (Simian sarcoma virus), encoded by the v-sis oncogene, is derived from the B chain of PDGF.

PDGFs are mitogenic during early developmental stages, driving the proliferation of undifferentiated mesenchyme and some progenitor populations. During later maturation stages, PDGF signalling has been implicated in tissue remodelling and cellular differentiation, and in inductive events involved in patterning and morphogenesis. In addition to driving mesenchymal proliferation, PDGFs have been shown to direct the migration, differentiation and function of a variety of specialised mesenchymal and migratory cell types, both during development and in the adult animal [ (PUBMED:12952899) ].

PDGF is structurally related to a number of other growth factors which also form disulphide-linked homo- or heterodimers.

This domain consists of the N-terminal regions of PGDF A and B.

GO component:membrane (GO:0016020)
GO function:growth factor activity (GO:0008083)

This is a PFAM domain. For full annotation and more information, please see the PFAM entry PDGF_N