Fig. 2.

(A) Omit electron density for n-src loop (residues 35–40) of chain A (DSH3), calculated without the loop during refinement (see Materials and Methods). The map was contoured at a 1.0 level of sigma. This figure was generated with Molray (http://portray.bmc.uu.se/cgi-bin/markh/molray.pl) and rendered with Povray (http://www.povray.org/). (B) Quaternary structure of DSH3 (magenta, blue) and MSH3 (green). The relative positions of folded SH3 molecules were compared. Subunits 1 and 2 (SU1 and SU2) for both DSH3 and MSH3 are labeled. The N terminus, C terminus, RT-loop, and n-src loops are shown. Note the strand exchange at the n-src loops.