(Opposite and above) Multiple
alignment and sequence comparison of RhoBTB proteins. (A)
Multiple alignment and domain structure of RhoBTB proteins. A search
of GenBank databases with the 400 residues long C-terminal part
of DdRacA led to the identification of the complete sequence of
one orthologue in Drosophila and three in human.
Proteins of this novel subfamily are composed of a GTPase domain,
a proline-rich region, two BTB domains (the first one divided into
two subdomains by intervening sequences; dashed line) and a C-terminal
domain of unknown function. Note that only HsRhoBTB3 ends with a prenylation
signal. Sequences were aligned with ClustalX. Dashes indicate gaps
introduced for optimal alignment. Residues identical or similar
in at least three sequences appear in a black or grey background,
respectively. Accession numbers are as follows: DmRhoBTB, AF217287;
HsRhoBTB1, KIAA0740; HsRhoBTB3, KIAA0717; HsRhoBTB3, KIAA0878. (B) Comparison of DdRacA with other RhoBTB proteins.
The numbers in each corresponding-colour region represent the percent
similarity of each major domain of RacA to any of the other RhoBTB
proteins. For the first BTB domain both subdomains have been calculated
separately.