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Interaction with free β′ subunit unmasks DNA‐binding domain of RNA polymerase σ subunit
Author(s) -
Kulbachinskiy Andrey,
Mustaev Arkady,
Goldfarb Alex,
Nikiforov Vadim
Publication year - 1999
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(99)00778-4
Subject(s) - rna polymerase , protein subunit , dna , specificity factor , polymerase , transcription bubble , microbiology and biotechnology , chemistry , biophysics , binding site , biology , escherichia coli , biochemistry , rna dependent rna polymerase , gene
The promoter recognition site on the σ 70 initiation factor is shielded from interaction with DNA unless σ 70 is bound to the core component of RNA polymerase (RNAP). It is shown that interaction of σ 70 with the isolated β′ subunit of Escherichia coli RNAP is sufficient to induce unshielding of the DNA binding site. Using UV‐induced DNA‐protein cross‐linking we demonstrate that free β′ stimulates specific cross‐links between region 2 of the σ 70 polypeptide and a fragment of the non‐template promoter strand containing the TATAAT sequence. Thus the σβ′ subassembly of RNAP can assume a functionally competent conformation independently of the bulk of the RNAP core.