Abstract:
:In order to study the mutagenic effects of site-specific, covalent modifications of biologically active DNA, we need host cells that are permissive for any type of mutation that might be produced in vivo from the modified DNA. Specifically, we require a general, in vivo complementation system for the bacteriophage phiX174 gene G, an essential gene that we have chosen for our initial studies of chemical mutagenesis. Toward this end, we have constructed a plasmid (pphiXG) that carries a functional copy of phiX174 gene G. Three different bacterial strains that are nonpermissive for am9, a gene G amber mutant, have been transformed with pphiXG. The transformants are now permissive for this gene G mutant, but not for the gene A or E mutants that have been tested. This paper describes the construction and the biochemical characterization of this plasmid, pphiXG, and describes some of the biological properties exhibited by the pphiXG-bearing strains.
journal_name
Proc Natl Acad Sci U S Aauthors
Humayun MZ,Chambers RWdoi
10.1073/pnas.75.2.774subject
Has Abstractpub_date
1978-02-01 00:00:00pages
774-8issue
2eissn
0027-8424issn
1091-6490journal_volume
75pub_type
杂志文章abstract::Estimation of evolutionary distances has always been a major issue in the study of molecular evolution because evolutionary distances are required for estimating the rate of evolution in a gene, the divergence dates between genes or organisms, and the relationships among genes or organisms. Other closely related issue...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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doi:10.1073/pnas.95.11.5899
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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doi:10.1073/pnas.0503728102
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:1980-02-01 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:1977-11-01 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:2010-06-01 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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abstract::Fusions of the lac operon to genes induced by treatment with sublethal levels of alkylating agents have been selected from random insertions of the Mu-dl(ApRlac) phage by screening for induction of beta-galactosidase activity in the presence of methyl methanesulfonate. Genetic analysis reveals that these fusions resul...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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abstract::Rap phosphatases are a recently discovered family of protein aspartate phosphatases that dephosphorylate the Spo0F--P intermediate of the phosphorelay, thus preventing sporulation of Bacillus subtilis. They are regulators induced by physiological processes that are antithetical to sporulation. The RapA phosphatase is ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:1996-02-20 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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doi:10.1073/pnas.97.4.1879
更新日期:2000-02-15 00:00:00
abstract::Analysis, by the recovery of specific genetic "markers," of the effects of DNase I, physical shear, and temperature shock on DNA-cell complexes demonstrates that sequential attachment of both ends of bacteriophage SP82G DNA to Bacillus subtilis precedes entry of the DNA molecule into the cell, and that each attachment...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.69.6.1545
更新日期:1972-06-01 00:00:00
abstract::Discovering the visual features and representations used by the brain to recognize objects is a central problem in the study of vision. Recently, neural network models of visual object recognition, including biological and deep network models, have shown remarkable progress and have begun to rival human performance in...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1513198113
更新日期:2016-03-08 00:00:00