BTF3 is evolutionarily conserved in fission yeast.

BTF3 is a protein initially identified in HeLa cells that may be involved in the initiation of transcription. Although its specific role in transcription is unclear, BTF3 can form a stable complex with RNA polymerase II. Recently, BTF3 has also been shown to bind to nascent polypeptide chains. We have cloned a homolog of BTF3 from the fission yeast, Schizosaccharomyces pombe. This homolog, spBTF3, encodes a putative 151 amino acid protein that shares 72% similarity with human BTF3, 73% similarity with the Caenorhabditis elegans homolog and between 52 and 53% similarity with the Saccharomyces cerevisiae homologs, EGD1 and BTT1.