CHARACTERIZATION OF THE ESCHERICHIA-COLI CODBA OPERON ENCODING CYTOSINE PERMEASE AND CYTOSINE DEAMINASE

被引：114

作者：

DANIELSEN, S

KILSTRUP, M

BARILLA, K

JOCHIMSEN, B

NEUHARD, J

机构：

[1] UNIV COPENHAGEN,INST BIOL CHEM B,SOLVGADE 83,DK-1307 COPENHAGEN K,DENMARK

[2] AARHUS UNIV,DEPT MOLEC BIOL,DK-8000 AARHUS,DENMARK

来源：

MOLECULAR MICROBIOLOGY | 1992年 / 6卷 / 10期

关键词：

D O I：

10.1111/j.1365-2958.1992.tb00854.x

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

The nucleotide sequence of a 3.1 kb segment carrying the cytosine deaminase gene (codA) from Escherichia coli was determined. The sequence revealed the presence of two open reading frames, the first (codB) specifying a highly hydrophobic polypeptide and the second specifying cytosine deaminase. A two-codon overlap between the two reading frames indicates that they constitute an operon. Transcription of the operon was found to be regulated by exogenous purines. Polypeptides specified by each of the two reading frames were expressed in minicells, and the codB gene product was found to be highly enriched in the membrane fraction. Uptake experiments showed that the CodB protein is required for cytosine transport into the cell and that the intracellular accumulation of cytosine correlated with the codB gene dose. A topological model for the cytosine permease in the cytoplasmic membrane is proposed.

引用

页码：1335 / 1344

页数：10

共 43 条

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