Inhibition of transcription of cytosine-containing DNA in vitro by the alc gene product of bacteriophage T4

Journal Article · Tue May 01 04:00:00 EDT 1990 · Journal of Bacteriology; (USA)

OSTI ID:6529300

Drivdahl, R H; Kutter, E M ^[1]

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1. Evergreen State College, Olympia, WA (USA)

The alc gene product (gpalc) of bacteriophage T4 inhibits the transcription of cytosine-containing DNA in vivo. The authors examined its effect on transcription in vitro by comparing RNA polymerase isolated from Escherichia coli infected with either wild-type T4D{sup +} or alc mutants. A 50 to 60% decline in RNA polymerase activity, measured on phage T7 DNA, was observed by 1 min after infection with either T4D{sup +} or alc mutants; this did not occur when the infecting phage lacked gpalt. In the case of the T4D{sup +} strain but not alc mutants, this was followed by a further decrease. By 5 min after infection the activity of alc mutants was 1.5 to 2.5 times greater than that of the wild type on various cytosine-containing DNA templates, whereas there was little or no difference in activity on T4 HMdC-DNA, in agreement with the in vivo specificity. Effects on transcript initiation and elongation were distinguished by using a T7 phage DNA template. Rifampin challenge, end-labeling with ({gamma}-{sup 32}P)ATP, and selective initiation with a dinucleotide all indicate that the decreased in vitro activity of the wild-type polymerase relative to that of the alc mutants was due to inhibition of elongation, not to any difference in initiation rates. Wild-type (but not mutated) gpalc copurified with RNA polymerase on heparin agarose but not in subsequent steps. Immunoprecipitation of modified RNA polymerase also indicated that gpalc was not tightly bound to RNA polymerase intracellularly.

• OSTI ID: 6529300
• Journal Information: Journal of Bacteriology; (USA), Journal Name: Journal of Bacteriology; (USA) Vol. 172:5; ISSN JOBAA; ISSN 0021-9193
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINES
ATP
AZINES
BACTERIA
BACTERIOPHAGES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CYTOSINE
DAYS LIVING RADIOISOTOPES
DNA
ENZYMES
ESCHERICHIA COLI
GENES
HETEROCYCLIC COMPOUNDS
IN VITRO
INHIBITION
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
MICROORGANISMS
MOLECULAR BIOLOGY
MUTANTS
NUCLEI
NUCLEIC ACIDS
NUCLEOTIDES
NUCLEOTIDYLTRANSFERASES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PARASITES
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PHOSPHORUS-GROUP TRANSFERASES
POLYMERASES
PYRIMIDINES
RADIOISOTOPES
RNA POLYMERASES
TRACER TECHNIQUES
TRANSCRIPTION
TRANSFERASES
VIRUSES