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S SPIEGELMAN

Publications and source records attributed to S SPIEGELMAN.

At least 19 recordsLinked to original sources
PubMed1965

CHROMATOGRAPHIC SEPARATION OF ANNEALED AND ENZYMATICALLY SYNTHESIZED RNA-DNA HYBRIDS.

A procedure is described for the chromatographic detection and isolation of DNA-RNA hybrids on columns of methylated albumin coated on kieselguhr (MAK). Its use is illustrated with both annealed and enzymatically synthesized hybrids. The method has the advantage of a wide range in capacity and resolution and permits actual isolation of the hybrid structure. It is uniquely effective in experiments involving hybridization with small DNA fragments.

Chromatography↗
PubMed1964

CIRCULARITY OF THE REPLICATING FORM OF A SINGLE-STRANDED DNA VIRUS.

Electron micrographs of purified replicating form DNA of the bacteriophage øX-174 show that it has ring structure. The circular property may explain both the abnormally high sedimentation coefficient and the great resistance of this DNA to irreversible heat denaturation. Intactness of the circle is required for the control of strand selection during transcription into complementary copies of RNA.

Chemical Phenomena↗
PubMed1963

TRANSLATIONAL CONTROL OF PROTEIN SYNTHESIS IN A CELL-FREE SYSTEM DIRECTED BY A POLYCISTRONIC VIRAL RNA.

Observations with RNA isolated from the RNA virus indicate that regulation of protein synthesis occurs during translation. At least three electrophoretically separable proteins, one of which lacks histidine, appear as a result of adding purified viral RNA to a cell-free extract of Escherichia coli. This establishes that the RNA contains at least three cistrons. Comparison of the kinetics of appearance of the proteins that do and do not contain histidine reveals a control mechanism which determines the temporal order and the frequency of translation of each cistron. Such translational controls at the stage of message use provide additional devices for regulating protein synthesis which can supplement those functioning at the transcription step where genetic messages are produced.

Carbon Isotopes↗
PubMed1962

Origin and biologic individuality of the genetic dictionary.

Deoxyribonucleic acid contains sequences complementary to homologous amino-acid transfer ribonucleic acid molecules which serve as the translating device between polyribonucleotides and proteins. This implies that the RNA molecules have their primary origin in DNA. From the amount of DNA participating, one would infer that more than 20 complementary sequences exist per genome, a conclusion consistent with a degenerate code. The fact that complex formation occurs most readily with homologous RNA suggests that, while the language remains universal, each dictionary is uniquely identifiable with its own genome.

Amino Acids↗
PubMed1962

Homology test between the nucleic acid of an RNA virus and the DNA in the host cell.

Deoxyribonucleic acid in the host cell does not contain a sequence complementary to the nucleic acid of an RNA virus. Specific formation of hybridbetween deoxyribonucleic acid and ribonucleic acid was used as a detecting device. The test was internally controlled and sensitive enough to reveal complementary stretches in the DNA corresponding to 10 percent of the viral ribonucleic acid. The implications of the results for replication and transcription of RNA are discussed.

Coliphages↗
PubMed1962

Size distribution of "informational" RNA.

Previous investigations suggested that the size of "informational" or "messenger" RNA was confined to sedimentation rates lying between 8 and 14S. These involved procedures permitting extended contact of the RNA with enzymatically active extracts. The present study re-examined the size distribution of T2-complementary RNA isolated by a method which minimized enzymatic degradation. A much greater diversity in size distribution (4S to 25S) was observed. Experiments are described indicating that 8 to 12S informational RNA does not readily attach to the 16S and 23S ribosomal components under the conditions used for sedimentation analysis.

Escherichia coli↗