Identification of a novel positive regulator of the 4-hydroxyphenylacetate catabolic pathway of Escherichia coli

被引:37
作者
Prieto, MA [1 ]
Garcia, JL [1 ]
机构
[1] CSIC,CTR INVEST BIOL,DEPT MOL MICROBIOL,E-28006 MADRID,SPAIN
关键词
D O I
10.1006/bbrc.1997.6368
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 hpa cluster of Escherichia coli W ATCC 11105 encodes the enzymes involved in the catabolism of 4-hydroxyphenylacetate (4-HPA). The catabolic genes are organized in two operons, the hpaBC operon, which produces the hydroxylase activity, and the meta operon, which encodes the enzymes that cleave the aromatic ring and allows its further metabolism. Using a monocopy or multicopy lacZ reporter system, we have demonstrated that the hydroxylase genes are transcribed from the P-BC promoter which is positively regulated by the hpaA gene product. HpaA is activated by 4-HPA, 3-HPA, or phenylacetate and represents a novel member of the AraC/XylS family of regulators that recognizes aromatic effecters. The -35 box of the PBC promoter clearly deviates from the consensus sigma(70) promoters of E. coli, but upstream of this box we observed two direct repeats, a common characteristic of promoters regulated by the AraC family of proteins. The hpaA gene, which appears to form a transcriptional unit with the putative hpaX transport gene, is also expressed from an alternative promoter that is located within the hpaX structural sequence. On the basis of these findings, we propose a working model for the regulation of the unique aromatic catabolic pathway thus far characterized at a molecular level in E. coli. This regulatory circuit opens a new scenario for the development of novel microbiological tools for environmental purposes. (C) 1997 Academic Press.
引用
收藏
页码:759 / 765
页数:7
相关论文
共 24 条
[1]   DIVISION GENES IN ESCHERICHIA-COLI ARE EXPRESSED COORDINATELY TO CELL SEPTUM REQUIREMENTS BY GEARBOX PROMOTERS [J].
ALDEA, M ;
GARRIDO, T ;
PLA, J ;
VICENTE, M .
EMBO JOURNAL, 1990, 9 (11) :3787-3794
[2]   CATABOLISM OF PHENYLPROPIONIC ACID AND ITS 3-HYDROXY DERIVATIVE BY ESCHERICHIA-COLI [J].
BURLINGAME, R ;
CHAPMAN, PJ .
JOURNAL OF BACTERIOLOGY, 1983, 155 (01) :113-121
[3]  
COOPER RA, 1985, J GEN MICORBIOL, V134, P2753
[4]   DESIGNING MICROBIAL SYSTEMS FOR GENE-EXPRESSION IN THE FIELD [J].
DELORENZO, V .
TRENDS IN BIOTECHNOLOGY, 1994, 12 (09) :365-371
[5]   DNA-DEPENDENT RENATURATION OF AN INSOLUBLE DNA-BINDING PROTEIN - IDENTIFICATION OF THE RHAS BINDING-SITE AT RHABAD [J].
EGAN, SM ;
SCHLEIF, RF .
JOURNAL OF MOLECULAR BIOLOGY, 1994, 243 (05) :821-829
[6]   THE XYLS/ARAC FAMILY OF REGULATORS [J].
GALLEGOS, MT ;
MICHAN, C ;
RAMOS, JL .
NUCLEIC ACIDS RESEARCH, 1993, 21 (04) :807-810
[7]  
GARCIA E, 1982, FEMS MICROBIOL LETT, V14, P133
[8]   FORMATION OF PILIN IN PSEUDOMONAS-AERUGINOSA REQUIRES THE ALTERNATIVE SIGMA-FACTOR (RPON) OF RNA-POLYMERASE [J].
ISHIMOTO, KS ;
LORY, S .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1989, 86 (06) :1954-1957
[9]   TOL plasmid transcription factor XylS binds specifically to the Pm operator sequence [J].
Kaldalu, N ;
Mandel, T ;
Ustav, M .
MOLECULAR MICROBIOLOGY, 1996, 20 (03) :569-579
[10]   GENETIC-EVIDENCE THAT THE XYLS REGULATOR OF THE PSEUDOMONAS TOL META OPERON CONTROLS THE PM PROMOTER THROUGH WEAK DNA-PROTEIN INTERACTIONS [J].
KESSLER, B ;
HERRERO, M ;
TIMMIS, KN ;
DELORENZO, V .
JOURNAL OF BACTERIOLOGY, 1994, 176 (11) :3171-3176