Abstract:
:We studied mutants of E. coli originally identified as being deficient in either endonuclease II (deoxyribonucleate oligonucleotidohydrolase, EC 3.1.4.30) or exonuclease III [deoxyribonucleate (double-stranded) 5'-nucleotidohydrolase, EC 3.1.4.27] activity. Twelve independently derived mutants were tested, including three new endonuclease II mutants. Deficiency of one enzyme was always accompanied by deficiency of the other. Furthermore, temperature-sensitivity of one activity was always accompanied by temperature-sensitivity of the other, and the enzymes were co-purified. The results suggested a physical association between exonuclease III and endonuclease II, which may be of advantage in the excision-repair of DNA. A thermolabile endonuclease II was purified from one of the new mutants, indicating that it had an altered structural gene. This mutation, and all similar ones mapped by genetic transduction, was located between the pncA and aroD genes on the E. coli chromosome. One mutant had a prolonged generation time, an increased sensitivity to the alkylating agents methyl-methanesulfonate and mitomycin C, and a decreased plating efficiency for bacteriophage lambda, but no marked sensitivity to ultraviolet or gamma-irradiation. Its enzymatic and biological abnormalities were simultaneously revertible, suggesting they were caused by a single mutation. These results suggested a role for these enzymes in normal cell growth processes and in the repair of alkylation damage.
journal_name
Proc Natl Acad Sci U S Aauthors
Yajko DM,Weiss Bdoi
10.1073/pnas.72.2.688keywords:
subject
Has Abstractpub_date
1975-02-01 00:00:00pages
688-92issue
2eissn
0027-8424issn
1091-6490journal_volume
72pub_type
杂志文章abstract::The glutathione S-transferases (GST) (glutathione transferase; EC 2.5.1.18) are a family of enzymes responsible for the metabolism of a broad range of xenobiotics and carcinogens. A cDNA clone containing the entire amino acid coding sequence of a human GST-2 subunit has been isolated using a lambda gt11 expression lib...
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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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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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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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:2007-09-04 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:2005-09-13 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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更新日期:1986-07-01 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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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:2011-09-20 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:2010-06-22 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:2009-03-03 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:2013-08-13 00:00:00
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更新日期:1992-04-01 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:2010-07-27 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:2009-05-05 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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更新日期:2012-11-20 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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更新日期:1987-09-01 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
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更新日期:2013-10-01 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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更新日期:2007-06-05 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:2011-10-04 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:2007-03-06 00:00:00