A TFIIB-like protein is indispensable for spliced leader RNA gene transcription in Trypanosoma brucei

摘要: The lack of general class II transcription factors was a hallmark the genomic sequences human parasites Trypanosoma brucei, cruzi and Leishmania major. However, recent identification TFIIA as part protein complex essential for RNA polymerase II-mediated SLRNA genes, which encode trans splicing-specific spliced leader RNA, suggests that trypanosomatids assemble highly divergent set these at promoter. Here we report trypanosomatid TFIIB-like (TFIIB(like)) has limited overall sequence homology to eukaryotic TFIIB archaeal TFB but harbors conserved residues within N-terminal zinc ribbon domain, B finger cyclin repeat I. In accordance with function TFIIB, T.brucei TFIIB(like) is encoded by an gene, localizes nucleus, specifically binds promoter, interacts II, absolutely required transcription.