Sequence and structural comparison of GEFs from different origins.

<p>(A) Sequence alignment of SopE-type (upper alignment) and WxxxE-type (lower alignment) bacterial effector proteins with postulated Rho GTPase activity; >80% identity is shaded in red, >50% in grey. The residues shown to be important for catalytic GEF activity of SopE <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1000795#ppat.1000795-Schlumberger1" target="_blank">[13]</a> or Map <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1000795#ppat.1000795-Huang1" target="_blank">[19]</a> are marked with asterisks. WxxxE motif and catalytic loops highlighted in (B) are marked with brackets. Note that SifA has a completely different amino acid sequence in its catalytic loop compared to the other proteins in the WxxxE family <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1000795#ppat.1000795-Huang1" target="_blank">[19]</a>. (B) Crystal structures of GEFs from different organisms in complex with Cdc42 (orange). Left panel: SopE (cyan) from <i>S.</i> Typhimurium <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1000795#ppat.1000795-Buchwald1" target="_blank">[12]</a>; the catalytic loop is highlighted in red. Middle panel: Map (pink) from enteropathogenic <i>E. coli </i><a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1000795#ppat.1000795-Huang1" target="_blank">[19]</a>; the WxxxE motif is highlighted in blue and the catalytic loop in red. Right panel: Human Tiam1 (pale blue); only the Rho GTPase binding DH domain is shown <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1000795#ppat.1000795-Worthylake1" target="_blank">[14]</a>. Structures were created using Jmol (<a href="http://www.jmol.org/" target="_blank">http://www.jmol.org/</a>).