ISSN:
1617-4623
Keywords:
ϕ 80 N gene
;
In vitro transcription
;
Antitermination
;
pN purification
;
pN complex
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary To confirm the in vivo observation that the N gene product of ϕ 80, ϕ 80-pN, prevents termination of transcription at the t L1 region and is therefore a transcription antitermination factor (Tanaka and Matsushiro 1985), we demonstrated that ϕ 80-t L1 is a ϱ-dependent terminator, similar to λ-t L1, and that ϕ 80-pN has a transcription antitermination function at this site in an in vitro transcription system using a nucleic acid-free S-100 extract. In the presence of ϱ-protein, transcription termination at t L1 was suppressed completely with an S-100 extract prepared from Escherichia coli strain NT525 containing the pBN1-N+ plasmid. Starting from this pN-overproducing cell extract, we purified ϕ 80-pN to homogeneity by chromatography on DEAE-Sephacel, Sephadex G-150 and CM-Sephadex C-50. The molecular weight of purified pN was about 12,000 and the NH2-terminal sequence was NH2-Met-Ile-Asp-Asp-Ile-Lys, which was consistent with the sequence deduced from the DNA sequence.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00338092
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