Escherichia coli exonuclease VII. Cloning and sequencing of the gene encoding the large subunit (xseA).
J Biol Chem
; 261(32): 14929-35, 1986 Nov 15.
Article
em En
| MEDLINE
| ID: mdl-3021756
ABSTRACT
We have determined the sequence of the gene encoding the large subunit of Escherichia coli exonuclease VII (xseA) and the amino acid sequence of the protein it encodes. The coding region of the xseA gene is 1368 base pairs. The protein encoded by the gene contains 456 amino acids and has a calculated molecular weight of 51,823. The promoter for xseA is close to that for guaB, and these two genes are transcribed in opposite directions xseA clockwise and guaB counterclockwise on the standard E. coli genetic map. The cloned xseA gene can complement an xseA deletion mutant strain. In an xseA+ genetic background production of large quantities of the xseA gene product appeared to decrease the amount of exonuclease VII activity in cell extracts. In fact, no exonuclease VII activity at all could be detected following induction of strains in which the xseA gene was under lambda pL regulation. These observations suggest that the proper ratio of the large and small exonuclease VII subunits must be maintained in order to produce active enzyme.
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01-internacional
Base de dados:
MEDLINE
Assunto principal:
Clonagem Molecular
/
Proteínas de Escherichia coli
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Escherichia coli
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Exodesoxirribonucleases
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Genes
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Genes Bacterianos
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
1986
Tipo de documento:
Article
País de publicação:
EEUU
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ESTADOS UNIDOS
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ESTADOS UNIDOS DA AMERICA
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EUA
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UNITED STATES
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UNITED STATES OF AMERICA
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US
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USA