Intrinsic promoter recognition by a "core" RNA polymerase.
Two classes of RNA polymerases transcribe RNA from promoters on DNA templates: promoter recognition-competent single polypeptides and multisubunit enzymes that require separable promoter recognition factors. Eukaryotic mitochondria utilize an unusual hybrid of these classes composed of a "core" RNA polymerase related to the single polypeptide enzymes plus a "specificity factor" necessary for promoter utilization. Using supercoiled or premelted templates, we have discovered that the yeast core mitochondrial RNA polymerase (Rpo41) has the intrinsic ability to initiate from promoters without its specificity factor (Mtf1). Rpo41 requires the mitochondrial promoter sequence (ATATAAGTA) for this activity. On premelted templates addition of Mtf1 actually inhibits the promoter selective activity of Rpo41. Mtf1 increases abortive relative to productive transcription by Rpo41, possibly by stabilizing the promoter complex and reducing escape into elongation. The requirement for Mtf1 on closed but not open templates indicates that Mtf1 facilitates melting but not recognition of promoters.
Matsunaga
Michio
M
Department of Biochemistry and Molecular Genetics and Program in Molecular Biology, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA.
Jaehning
Judith A
JA
D001483:Base Sequence; D004247:DNA / Q000737:chemistry; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D008928:Mitochondria / Q000473:pathology; D024101:Mitochondrial Proteins; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010957:Plasmids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D017434:Protein Structure, Tertiary; D012335:RNA, Ribosomal / Q000737:chemistry; D012343:RNA, Transfer / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism; D013379:Substrate Specificity; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
C071720:MTF1 protein, S cerevisiae; D024101:Mitochondrial Proteins; D012335:RNA, Ribosomal; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D004247:DNA; D012343:RNA, Transfer; D012321:DNA-Directed RNA Polymerases; C487996:RPO41 protein, S cerevisiae