Figure 4.

The RGD finger is an evolutionary insertion unique to the EGF domains of Del-1 and MFG-E8. A) The top 13 hits of DALI search for Del-1 EGF2 domain. Compared to these known EGF structures, the Del-1 EGF2 domain appears to have an RGD motif inserted between cysteines C³ and C⁴. B) List of known EGF domains containing an RGD motif resulting from a genome-wide search. C) Locations of an RGD finger shown in panel B are displayed on the Del-1 EGF2 structure. Six cysteines in orange are labeled. Yellow, cyan, and dark blue regions indicate where an RGD motif positions in panel B.