Fig. 4.

A different M domain position in the Ffh·FtsY complex. (A) Mapping of T. aquaticus Lys-386^Ffh, Lys-390^Ffh, and Lys-404^Ffh on the structure of S. solfataricus SRP54. S. solfataricus SRP54 (gray) was superimposed with Ffh (green) of T. aquaticus Ffh·FtsY NG domain complex (green, Ffh; blue, FtsY). Residues that cross-linked to Gly(-3)^Ffh are shown as sticks in magenta. (B) A close proximity of the M domain toward Ffh·FtsY complex interface, suggested by the cross-linking data. Magenta asterisks, relevant cross-linked residues; lines, cross-links; gray cylinders, different positions of the M domain.