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S Mak

Publications and source records attributed to S Mak.

7 recordsLinked to original sources
PubMed1979

Structure and function of adenovirus type 12 defective virions.

Purified human adenovirus type 12 preparations contain defective virions with a lighter density. These defective virions were isolated, and their biological functions and DNA were characterized. They can induce early and late antigens in infected cells and tumors in newborn hamsters with similar efficiency as complete virions. The majority of the DNA molecules from light virions contain deletions mapping near 16% from the left-hand end of the genome. Mechanisms for the generation of these molecules are discussed.

Adenoviruses, Human↗
PubMed1978

Transcription map for adenovirus type 12 DNA.

The regions of the adenovirus type 12 genome which encode l- and r-strand-specific cytoplasmic RNA were mapped by the following procedure. Radioactive, intact, separated complementary strands of the viral genome were hybridized to saturating amounts of unlabeled late cytoplasmic RNA. The segments of each DNA strand complementary to the RNA were then purified by S1 nuclease digestion of the hybrids. The arrangement of the coding regions of each strand was deduced from the pattern of hybridization of these probes to unlabeled viral DNA fragments produced by digestion with EcoRI, BamHI, and HindIII.. The resulting map is similar, if not identical, to that of adenovirus type 2. The subset of the late cytoplasmic RNA sequences which are expressed at early times were located on the map by hybridizing labeled, early cytoplasmic RNA to both unlabeled DNA fragments and unlabeled complementary strands of specific fragments. Early cytoplasmic RNA hybridized to the r-strand to EcoRI-C and BamHI-B and to the l-strand of BamHI-E. Hybridization to BamHI-C was also observed. The relative rates of accumulation of cytoplasmic RNA complementary to individual restriction fragments was measured at both early and late times. Early during infection, most of the viral RNA appearing in the cytoplasm was derived from the molecular ends of the genome. Later (24 to 26 h postinfection) the majority of the newly labeled cytoplasmic RNA was transcribed from DNA sequences mapping between 25 and 60 map units on the genome.

Adenoviruses, Human↗
PubMed1976

Purification of adenovirus messenger ribonucleic acid by an aqueous polymer two-phase system.

An aqueous polymer phase system containing 6.3% (w/w) dextran and 3.5% (w/w) poly(ethylene glycol) in 10 mM phosphate buffer (pH 8.0) was developed to select RNA-DNA hybrids from unhybridized RNA. The top phase of this phase system, which contains DNA and the RNA-DNA hybrids, can be used to purify adenovirus messenger RNA both early and late in the infectious cycle. The hybrids can be melted by heat in the top phase and the messenger RNA selected by oligo(dT)cellulose chromatography whereupon the polymers and the DNA percolate and the polyadenylated messenger RNA absorb to the column. The isolated messenger RNA appears to be almost quantitatively recovered at a purity from 70 to 90% depending on the concentration of the specific messenger RNA in the starting material. Early and late viral messenger RNA were selected on the complementary strands of adenovirus DNA according to this procedure.

Adenoviruses, Human↗