Contrast alignments showing the most distinctive sequence features of P-loop GTPases and of Rab-related GTPases. See legends to Figures 1B,C for descriptions. (A) Distinctive sequence features of P-loop GTPases. The acronym 'GBL' stands for guanine-binding loop. (B) Distinctive sequence features of Rab-related GTPases. The foreground (Rab-related GTPases) includes Rab, Ran, Rho and some (but not all) Ras family GTPases; the background consists of other Ras-like GTPases.