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Role of the RNA polymerase α subunit in transcription activation
Author(s) -
Ishihama Akira
Publication year - 1992
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.1992.tb02196.x
Subject(s) - biology , rna polymerase , specificity factor , transcription (linguistics) , protein subunit , rna polymerase ii , transcription factor ii d , polymerase , microbiology and biotechnology , rna polymerase i , general transcription factor , rna polymerase ii holoenzyme , genetics , rna , promoter , dna , gene , gene expression , linguistics , philosophy
Summary The N ‐terminal two‐thirds of the α subunit of Escherichia coli RNA polymerase plays an essential role in the initiation of subunit assembly, by gathering two large subunits, β and β', together into a coreenzyme complex. One group of RNA polymerase mutants deficient in response to transcription activation carries mutations in the C ‐terminal region of the α subunit, indicating that the C ‐terminal region of the a subunit is involved in protein‐protein contact in positive control of transcription. A set of activators (class I transcription factors) which make contact with this contact site I region on RNA polymerase a subunit bind in most cases to DNA upstream of the promoter ‐35 signal. Genetic fine mapping indicates that a cluster of subsites exists in the contact site I region, each interacting with a set of the class I factors and each consisting of a structure formed by only 5‐10 amino acid residues.