Blastocystis elongation factor-1 alpha: genomic organization, taxonomy andphylogenetic relationships

The elongation factor-1 alpha (eF-1 alpha) is a highly conserved ubiquitous protein that is involved in translation and is desirable fur use in phylog enetic studies on Blastocystis, an enigmatic intestinal parasite with a con tentious taxonomic position. In the result study, a PCR product (BE alpha) that codes for a major part of the coding region of the EF-1 alpha protein was amplified. Genome walking experiments together with cloning were implem ented to elucidate the 5' and 3' ends of the EF-1 alpha, gene of the human isolate, Blastocystis hominis C. The genomic organization and the potential transcription factor binding sites of the 5' end of B. hominis C EF-1 alph a were identified. A comparative study on the deduced amino acid sequences of BE alpha of 13 Blastocystis isolates from various hosts was done to eval uate the phylogenetic relationship among the species dagger. A phylogenetic reconstruction analysis with other eukaryotic EF-1 alpha sequences was car ried out to trace the phylogenetic position of Blastocystis among eukaryoti c organisms.