1i4w
THE CRYSTAL STRUCTURE OF THE TRANSCRIPTION FACTOR SC-MTTFB OFFERS INTRIGUING INSIGHTS INTO MITOCHONDRIAL TRANSCRIPTION
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| , resolution 2.60Å | |||||||
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| Ligands: | |||||||
| Gene: | MTF1 (Saccharomyces cerevisiae) | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
OverviewOverview
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.
About this StructureAbout this Structure
1I4W is a Single protein structure of sequence from Saccharomyces cerevisiae. Full crystallographic information is available from OCA.
ReferenceReference
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
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