A novel gene encoding a ras-like GTP-binding protein from Trypanosoma brucei: an evolutionary ancestor of the ras and rap genes of higher eukaryotes?

摘要: The ras superfamily of GTP binding proteins encompasses a wide range family members, related by conserved amino-acid motifs, and act as molecular binary switches that play key roles in cellular processes. Gene duplication divergence has been postulated the mechanism which such members have evolved their specific functions. We cloned sequenced ras-like gene, tbrlp, from primitive eukaryote Trypanosoma brucei. gene encodes protein 227 amino acids contains six subdomains designate it ras/rap subfamily member. However, presence diagnostic residues characteristic both rap families confuse familial classification this gene. Phylogenetic analysis domain places its origins at point suggests tbrlp is an ancestral to genes higher eukaryotes.