Minimal Machinery of RNA Polymerase Holoenzyme Sufficient for Promoter Melting

• Published in: Science (American Association for the Advancement of Science) Vol. 303; no. 5662; pp. 1382 - 1384
• Main Authors: Young, Brian A., Gruber, Tanja M., Gross, Carol A.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 27.02.2004; The American Association for the Advancement of Science
• Subjects: Amino acids; Bacteriology; Biochemistry; Biological and medical sciences; Chemical properties; DNA; DNA, Bacterial - chemistry; DNA, Bacterial - genetics; DNA, Bacterial - metabolism; DNA, Superhelical - chemistry; DNA, Superhelical - genetics; DNA, Superhelical - metabolism; DNA-Directed RNA Polymerases - chemistry; DNA-Directed RNA Polymerases - metabolism; Enzymes; Escherichia coli; Escherichia coli - enzymology; Escherichia coli - genetics; Fundamental and applied biological sciences. Psychology; Genetic aspects; Genetic mutation; Genetic transcription; Growth, nutrition, cell differenciation; Heparin; Holoenzymes - chemistry; Holoenzymes - metabolism; Housework; Literary Devices; Melting; Microbiology; Models, Molecular; Mutation; Nucleic Acid Conformation; Promoter regions; Promoter Regions, Genetic; Protein Conformation; Protein Structure, Tertiary; RNA; RNA polymerase; RNA polymerases; Sigma Factor - chemistry; Sigma Factor - metabolism; Templates, Genetic; Transcription (Genetics); Transcription, Genetic; Zinc Fingers; United States; Nucleotidyltransferases; Melting; Enzyme; Transcription promoter; Transferases; Escherichia coli; Bacteria; DNA-directed RNA polymerase; Holoenzyme; Transcription initiation; Structure function relationship; Enterobacteriaceae
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1092462

We determined the minimal portion of Escherichia coli RNA polymerase (RNAP) holoenzyme able to accomplish promoter melting, the crucial step in transcription initiation that provides RNAP access to the template strand. Upon duplex DNA binding, the N terminus of the β' subunit (amino acids 1 to 314) and amino acids 94 to 507 of the σ subunit, together comprising less than one-fifth of RNAP holoenzyme, were able to melt an extended -10 promoter in a reaction remarkably similar to that of authentic holoenzyme. Our results support the model that capture of nontemplate bases extruded from the DNA helix underlies the melting process.