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Publication Abstract from PubMed

Although it is commonly accepted that binding of mitochondrial transcription factor sc-mtTFB to the mitochondrial RNA polymerase is required for specific transcription initiation in Saccharomyces cerevisiae, its precise role has remained undefined. In the present work, the crystal structure of sc-mtTFB has been determined to 2.6 A resolution. The protein consists of two domains, an N-terminal alpha/beta-domain and a smaller domain made up of four alpha-helices. Contrary to previous predictions, sc-mtTFB does not resemble Escherichia coli sigma-factors but rather is structurally homologous to rRNA methyltransferase ErmC'. This suggests that sc-mtTFB functions as an RNA-binding protein, an observation standing in contradiction to the existing model, which proposed a direct interaction of sc-mtTFB with the mitochondrial DNA promoter. Based on the structure, we propose that the promoter specificity region is located on the mitochondrial RNA polymerase and that binding of sc-mtTFB indirectly mediates interaction of the core enzyme with the promoter site.

Crystal structure of the transcription factor sc-mtTFB offers insights into mitochondrial transcription.,Schubot FD, Chen CJ, Rose JP, Dailey TA, Dailey HA, Wang BC Protein Sci. 2001 Oct;10(10):1980-8. PMID:11567089^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.