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Interaction of bacteriophage T4 AsiA protein with Escherichia coli σ 70 and its variant
Author(s) -
Pahari Susanta,
Chatterji Dipankar
Publication year - 1997
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(97)00668-6
Subject(s) - escherichia coli , bacteriophage , chemistry , microbiology and biotechnology , physics , biology , biochemistry , gene
Bacteriophage T4 produces a small protein AsiA , which inhibits transcription from σ 70 ‐dependent promoters in E. coli by tightly binding to σ 70 and is therefore termed as anti‐sigma factor. We observed that there was no inhibition of single round transcription at lac UV5 promoter when AsiA was added to preformed open complex between RNA polymerase and template DNA. However, transcription was found to proceed normally at ‘extended −10’ promoters in the presence of AsiA . It appears therefore that AsiA binds σ 70 at its 4.2‐subdomain or in its close vicinity. Further experiments on immunoprecipitation of σ 70 and a mutant σ 70 ‐V576G with AsiA seem to corroborate such conclusion.