A study in evolution: the DNA base sequence homology between coliphages T7 and T3
Journal of Molecular BiologyPublished 1 December 1971
Ronald W. Davis, Richard W. Hyman
Citations235
SJR quartileQ1
SJR score2.21
SNIP1.13
Generate an AI Snapshot to get a quick, structured summary of this paper.
Study Snapshot
ObjectiveStudy objective
MethodsResearch methodology
PopulationPopulation studied
Sample sizeSample sizes
OutcomesStudy outcomes here
ResultsStudy results comes here
LimitationsResearch study limitations comes here
A concise AI-generated summary of the paper will appear here once you click Generate AI Snapshot.
TL;DR
The observation that the fraction of the heteroduplex observed as double-stranded decreases with an increase in denaturing conditions indicates that the DNA's of T7 and T3 have extensive sequences of partial homology.
Abstract
As part of a continuing effort to understand evolution on the basis of comparing the base sequences of related coliphage DNA's, the heteroduplex T7M-T3L has been constructed in vitro and directly observed in the electron microscope. The fraction of the heteroduplex observed as double-stranded decreases with an increase in denaturing conditions. This observation indicates that the DNA's of T7 and T3 have extensive sequences of partial homology. There are base changes throughout most of the genome. The terminal redundancies are non-homologous. However, there is little change in the sequence of the structural genes 8, 15, 16 and 17, and in the sequence of the early messenger RNA promoter and termination sites.
Keywords
Biochemistry, Genetics and Molecular Biology
Journal of Molecular BiologyKinetics of renaturation of DNA
1,433 Citations1968James G. Wetmur, Norman Davidson
It is proposed that the mechanism of the reaction involves the joining of short, homologous sites on the two strands followed by a fast, reversible zippering reaction with forward rate constant kt, which explains the temperature and the GC dependence.
BiochemistryNucleic acid reassociation in formamide
603 Citations1969Betty L. McConaughy, Charles D. Laird +1 more
The present study explores in detail the relationships among the rate and specificity of reaction, the temperature, and the concentrations of formamide and salt.
NatureNew RNA Polymerase from Escherichia coli infected with Bacteriophage T7
544 Citations1970Michael J. Chamberlin, JANET MCGRATH +1 more
A new T7-specific RNA polymerase is found in T7 phage-infected cells and provides a direct explanation for the pleiotropic control of late T7 functions exerted by gene I.
VirologyThe genetics and physiology of bacteriophage T7
521 Citations1969F. William Studier
It appears that in T7 (as in T4 and lambda) related functions tend to cluster along the genetic map, which makes this system a very attractive one in which to study a number of biological problems at the molecular level.
Journal of Molecular BiologyA single-stranded deoxyribonucleic acid from bacteriophage φX174
506 Citations1959Robert L. Sinsheimer
It is concluded that the DNA of bacteriophage φX174 is single-stranded, and light scattering studies indicate that this DNA is highly flexible and that its configuration is strongly dependent upon the ionic strength of the solution.
NatureRate of Fixation of Nucleotide Substitutions in Evolution
505 Citations1969Charles D. Laird, Betty L. McConaughy +1 more
The initial rate of nucleotide sequence variation among rodents is ten-fold higher than that among artiodactyls when divergence time is estimated in years, and this difference diminishes if generations, rather than years, represent the appropriate interval of evolutionary divergence.
ScienceMapping of Deletions and Substitutions in Heteroduplex DNA Molecules of Bacteriophage Lambda by Electron Microscopy
408 Citations1969Barbara C. Westmoreland, Waclaw Szybalski +1 more
Electron microscopy of heteroduplex DNA molecules, composed of one strand of Escherichia coli phage λ+ DNA annealed to the complementary DNA strand of a λ deletion or substitution mutant, permits visualization, as well as precise measurements and mapping, of the unpaired single-stranded regions of nonhomology in the otherwise double- Stranded molecules.
Quarterly Reviews of BiophysicsEvolution of higher-organism DNA
326 Citations1970David E. Kohne
A great deal of information about evolutionary events and processes has been inferred from careful studies of fossil records, and comparison of DNA seems most promising since a relatively precise quantitative comparison can be made of all of the genetic material of different species.
Journal of Molecular BiologyDeletion mutants of bacteriophage lambda
286 Citations1971John S. Parkinson, Robert J. Huskey
All of the nearly 200 deletion mutants studied are defective in the ability to promote recombination in recombinationless host bacteria and fall into three major classes with respect to their integration behavior in different host strains.
VirologyTotally asymmetric transcription of coliphage T7 in vivo: Correlation with poly G binding sites
183 Citations1968William C. Summers, Waclaw Szybalski
The fact that the poly G-binding, deoxycytidylate (dC)-rich clusters are restricted to the in vivo transcribing H strand, together with the absence of thymine-rich clusters in T7 DNA, is compatible with the hypothesis that pyrimidine- rich clusters are related to RNA transcription, possibly as the initiation and termination sites.
VirologyT7-directed protein synthesis
182 Citations1969F. William Studier, Jacob V. Maizel
The protein composition of purified T7 phage particles, the patterns of protein synthesis after infection with wild-type and amber mutants of T7, and molecular weights of the individual polypeptide chains have been examined by electrophoresis on polyacrylamide gels containing SDS at neutral pH.
Journal of Molecular BiologyTerminal repetition in non-permuted T3 and T7 bacteriophage DNA molecules
142 Citations1967D.A. Ritchie, C.A. Thomas +2 more
T3 and T7 DNA molecules are terminally repetitious but non-permuted; T2 DNA is terminally repetition and permuted.
Journal of Molecular BiologyKinetics of the in vitro inhibition of transcription by actinomycin
135 Citations1970Richard W. Hyman, Norman Davidson
The membrane filter experiments in conjunction with the kinetics experiments suggest that when RNA polymerase, DNA and the purine triphosphates are mixed in a low salt medium, an initiation complex is formed at a specific site on T7 DNA and that the complex does not dissociate at high salt.
Journal of Molecular BiologyMolecular weights of coliphages and coliphage DNA
127 Citations1970Stuart B. Dubin, George B. Benedek +2 more
The molecular weights of the coliphages T4, T5 and T7 have been determined by measurement of their diffusion coefficient (D) and sedimentation coefficients (S) using the new technique of optical mixing spectroscopy.
Nature New BiologyDifferent Template Specificities of Phage T3 and T7 RNA Polymerases
122 Citations1971John J. Dunn, Friedlinde A. Bautz +1 more
Chamberlin et al. have separated the gene 1 product from the host enzyme in Escherichia coli and show that gene 1 codes for an entirely new RNA polymerase whioii transcribes T7 DNA efficiently and exclusively compared with other templates.
Journal of Molecular BiologyCo-operative non-enzymic base recognition
121 Citations1970Manfred Eigen, Dietmar Pörschke
Results show that the stacking between adjacent base pairs is the main source of stabilisation and that the enthalpy of base pairing in the co-operative model is mainly given by the ent Halpy of stacking.
Journal of Molecular BiologyThe physical properties of T7 bacteriophage
112 Citations1962Peter F. Davison, David Freifelder
The growth and purification of phage T7 is described and it was found that DNA comprises 50% of the particle.
Journal of Molecular BiologyMolecular weights of coliphages and coliphage DNA
102 Citations1970Frank C. Bancroft, David Freifelder
The range of usefulness of the high-speed equilibrium centrifugation method of Yphantis has been extended to measure the molecular weight of Escherichia coli phage T7, and the values yielded by the two techniques are in excellent agreement.
NatureTranscription of Late Phage RNA by T7 RNA Polymerase
99 Citations1970William C. Summers, Ruth B. Siegel
The RNA polymerase coded by phage T7 specifically transcribes the late regions of T7 DNA in vitro.
Journal of Molecular BiologyMolecular weights of homogeneous coliphage DNA's from density-gradient sedimentation equilibrium
89 Citations1969Carl W. Schmid, John E. Hearst
The concentration distributions at sedimentation equilibrium are studied as a function of DNA concentration for T7, T5 and T4 coliphage DNA's and the results extrapolated to infinite dilution to obtain molecular weights for these DNA's.
Journal of Molecular BiologyCalibration of molecular weight scales for DNA
89 Citations1969Sara B. Leighton, Irwin Rubenstein
The molecular weights of T2, T 5st + , T5st-0 and T7 DNA's were found by molecular autoradiographic determination of the phosphorus content of the phage DNA and/or the phages particle by determining the sedimentation rates in sucrose gradients.
Journal of Molecular BiologyThe process of infection with coliphage T7
87 Citations1970Ruth B. Siegel, William C. Summers
The results suggest that while gene 1 is transcribed in the absence of phage protein synthesis, the gene 1 protein is required to transcribe the remainder of the T7 genome by means of positive regulation.
Journal of Molecular BiologyPhysical mapping of T7 messenger RNA
74 Citations1971Richard W. Hyman
The techniques of electron microscopy have been used to observe directly the RNA-DNA hybrid constructed in vitro of an in vivo messenger RNA synthesized after T7 infection and the separated r -stfand of T7 DNA.
VirologyA study of the base sequence homology among the T series of bacteriophages
70 Citations1962Carl L. Schildkraut, K.L. Wierzchowski +3 more
A high degree of homology was found between pairs of T-even phage DNA and between the DNA from T3 and T7, and no indication of homologous links were found between DNA fromT-even and T-odd phages, nor between these and Escherichia coli DNA.
Journal of General VirologyHeat-stable and Density Mutants of Phages T1, T3 and T7
42 Citations1970D.A. Ritchie, F. E. Malcolm
Journal of BacteriologyCLASSIFICATION OF BACTERIAL VIRUSES: THE RELATIONSHIP OF TWO SERRATIA PHAGES TO COLI-DYSENTERY PHAGES T3, T7, AND D44
41 Citations1954Mark H. Adams, Evelyn Wade
Routine serological testing of a number of strains of bacteriophage indicated that some of them were related serologically to coliphages T3 and T7, and five phage strains were identified, one of which was dysentery phage D44, placed by Burnet (1933) in serological group 2 of the coli-dysentary phages.
Journal of Molecular BiologyA physical map of the left arm of the lambda chromosome
21 Citations1971John S. Parkinson, Ronald W. Davis
A comparison of the physical and genetic maps of the left arm indicates that there is a uniform probability of recombination per unit distance throughout this region of the lambda genome.