hLsg1 is member of a large circularly permuted GTPase family. (A) Schematic representation of hLsg1 – hLsg1 encodes a protein of 658 amino acids comprising a central MMR/HSR1 GTPase domain (black box, 151–500), a coiled-coil domain (Hatched box, 126–151) and a nuclear localization signal (NLS, grey box, 638–654). Domain organization of the GTPase is indicated as well as the insertion (white box inside the black box, 220–320) separating the G4 motif from the G1 motif. (B) Phylogenetic tree of the YRG superfamily. We constructed a multiple alignment of representative sequences from the YqeH, YjeQ, EngA, and YlqF families. The alignment was produced using ClustalW followed by manual editing . The tree was generated from the alignment using MrBayes v3  (100000 generations with parameter n chains = 4; convergence occurred after 33600 generations; the tree is the consensus of 664 trees computed using MrBayes. No molecular clock was assumed and therefore the branch lengths have no meaning. The numbers indicate the fraction of trees displaying the grouping given by the branch). The root of the tree is the one given by the MrBayes output. (C) Distribution of YRG members in cellular compartments in different organisms.