Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.6 (RNA polymerase)
 34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The transcription in vitro of eucaryotic tRNA genes by RNA polymerase III requires two transcription factors, designated TFIIIB and TFIIIC. One of the critical functions of TFIIIC in the transcription of tRNA genes is that it interacts directly and specifically with the two internal promoter elements of these genes. We have partially purified Saccharomyces cerevisiae TFIIIC by chromatography on Bio-Rex 70, DEAE-cellulose, and phosphocellulose resins. A 150-kilodalton (kDa) DNA-binding polypeptide copurified with TFIIIC activity. This 150-kDa protein coeluted with the DNA-binding activity of TFIIIC after rechromatography of TFIIIC on phosphocellulose and its elution with a linear salt gradient. The stable and high-affinity interaction of this protein with tRNA genes was demonstrated by the maintenance of a protein-DNA complex under conditions of high ionic strength. Finally, we showed by two criteria that the interaction of this protein with tRNA genes was specific. First, the protein-DNA complex was competed with only by DNA-containing tRNA genes; second, the protein preferentially bound to DNA fragments containing a tRNA gene. These results strongly suggest that the DNA-binding domain of the yeast TFIIIC is contained within this 150-kDa polypeptide.
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PMID:Identification of a 150-kilodalton polypeptide that copurifies with yeast TFIIIC and binds specifically to tRNA genes. 266 66

A protein--DNA complex containing TFIID has been analyzed by crosslinking. The TBP subunit of TFIID crosslinked to the TATA element but not to any of the regions further downstream which were tested. A 150 kd polypeptide, which corresponds in size to one of the TBP-associated factors (TAFs), crosslinked to a region between +10 and +15 and a second region between +35 and +47. Another polypeptide of greater than 205 kd (also a potential TAF) crosslinked preferentially to the region between +35 and +42. The +10 to +15 region has been recently implicated in hsp70 promoter recognition by TFIID, and the most downstream contacts overlap with the region where RNA polymerase II pauses on the hsp70 promoter in noninduced cells. Crosslinking revealed that as the salt concentration was increased, the TBP interaction was largely unaffected whereas the protein/DNA interactions downstream of the TATA element were disrupted. We propose that during the formation of a transcription complex, TATA-dependent interactions could be disrupted in the vicinity of the start site and the region immediately downstream. A protein contact downstream of +35 might function in pausing polymerase.
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PMID:Protein/DNA crosslinking of a TFIID complex reveals novel interactions downstream of the transcription start. 813 22