R
Robert B. Helling
Researcher at University of Michigan
Publications - 29
Citations - 3586
Robert B. Helling is an academic researcher from University of Michigan. The author has contributed to research in topics: Escherichia coli & Chloroplast DNA. The author has an hindex of 19, co-authored 29 publications receiving 3429 citations. Previous affiliations of Robert B. Helling include University of California, San Francisco.
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Journal ArticleDOI
Construction of Biologically Functional Bacterial Plasmids In Vitro
TL;DR: Newly constructed plasmids that are inserted into Escherichia coli by transformation are shown to be biologically functional replicons that possess genetic properties and nucleotide base sequences from both of the parent DNA molecules.
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Analysis of endonuclease R-EcoRI fragments of DNA from lambdoid bacteriophages and other viruses by agarose-gel electrophoresis.
Robert B. Helling,Robert B. Helling,Howard M. Goodman,Howard M. Goodman,Herbert W. Boyer,Herbert W. Boyer +5 more
TL;DR: By means of agarose-gel electrophoresis, endonuclease R.EcoRI-generated fragments of DNA from various viruses were separated, their molecular weights were determined, and complete or partial fragment maps for lambda, phi80, and hybrid phages were constructed.
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Replication and transcription of eukaryotic DNA in Escherichia coli.
John Morrow,Stanley N. Cohen,Annie C. Y. Chang,Herbert W. Boyer,Howard M. Goodman,Robert B. Helling +5 more
TL;DR: Fragments of amplified Xenopus laevis DNA, coding for 18S and 28S ribosomal RNA and generated by EcoRI restriction endonuclease, have been linked in vitro to the bacterial plasmid pSC101; and the recombinant molecular species have been introduced into E. coli by transformation.
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Evolution of Escherichia coli during Growth in a Constant Environment
TL;DR: Factors involved in the development of this polymorphism included differences in the maximum specific growth rate and in the transport of glucose, and excretion of metabolites by some clones which were utilized by minority clones.
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Why does Escherichia coli have two primary pathways for synthesis of glutamate
TL;DR: The results of competition experiments between the wild type and a GDH-deficient mutant during nutrient-limited growth and of direct enzyme measurements suggest that GDH is used in glutamate synthesis when the cell is limited for energy but ammonium and phosphate are present in excess, while the glutamine synthetase-glutamate synthase pathway is used when thecell is not under energy limitation.