Figure 6

Relationship of hvMSH oligomerization interfaces to N-terminal clasps and connecting segments in MSA and MSG. Superposition of hvMSH, ecMSA and ecMSG ternary complexes using SSM in Coot. a) N-terminal domain. MSA and MSG are shown as cartoon ribbon traces with N-terminal (NTD) and C-terminal (CTD) domains colored blue and red respectively. Only portions of the CTD which are not homologous to hvMSH are visible. MSH is shown as a green solvent-accessible surface. Other MSH subunits which make up a trimeric assembly are rendered as copper and yellow mesh surfaces; the subunits of the symmetry-related trimer which forms the hexameric assembly are colored grey and shown as mesh surfaces surrounding cartoon ribbon traces. b) Locations of connecting loops; view is from the right side of part a. MSH is shown as a molecular surface with the barrel domain and C-terminal domain colored green and red respectively. Extended surface loops (ESL; blue) connecting the NTD to barrel domains, and loops (orange) connecting barrel domains to the CTD in MSA and MSG are shown as cartoon ribbon traces. The segments of the connection between the barrel domain and CTD of MSH which are visible in electron density maps are depicted as a red cartoon ribbon trace. c) View identical to b, but including other subunits of the trimeric and hexameric hvMSH assembly colored and rendered as in part a.