Demonstration that the TyrR protein and RNA polymerase complex formed at the divergent P3 promoter inhibits binding of RNA polymerase to the major promoter, P1, of the aroP gene of Escherichia coli

被引:21
作者
Wang, PX
Yang, J
Ishihama, A
Pittard, AJ [1 ]
机构
[1] Univ Melbourne, Dept Microbiol, Parkville, Vic 3052, Australia
[2] Natl Inst Genet, Dept Mol Genet, Mishima, Shizuoka 411, Japan
关键词
D O I
10.1128/JB.180.20.5466-5472.1998
中图分类号
Q93 [微生物学];
学科分类号
071005 ; 100705 ;
摘要
In previous studies, we have identified three promoters (P1, P2, and P3) in the regulatory region of the Escherichia coli aroP gene (P. Wang, J. Yang, and A. J. Pittard, J. Bacteriol. 179:4206-4212, 1997). Both P1 and P2 can direct mRNA synthesis for aroP expression, whereas P3 is a divergent promoter which overlaps with P1. The repression of transcription from the major promoter, P1, has been postulated to involve the activation of the divergent promoter, P3, by the TyrR protein (P. Wang, J. Yang, B. Lawley, and A. J. Pittard, J. Bacteriol. 179:4213-4218, 1997). In the present study, we confirmed the proposed mechanism of P3-mediated repression of P1 transcription by studying the binding of RNA polymerase to the promoters P1 and P3 in vitro in the presence and absence of TyrR protein and its cofactors. Our results show that (i) only one RNA polymerase molecule can bind to the DNA fragment carrying the aroP regulatory region, (ii) RNA polymerase has a higher affinity for P1 than for either P2 or P3 and binds to P1 in the absence of TyrR protein, (iii) in the presence of TyrR protein and its cofactor, phenylalanine or tyrosine, RNA polymerase preferentially binds to P3, and (iv) RNA polymerase does not respond to the activation-defective mutant TyrR protein TyrR-RQ10 and remains bound to P1 in the presence of TyrR-RQ10 and either of the cofactors.
引用
收藏
页码:5466 / 5472
页数:7
相关论文
共 22 条
[1]   REPRESSION AND ACTIVATION OF TRANSCRIPTION BY GAL AND LAC REPRESSORS - INVOLVEMENT OF ALPHA-SUBUNIT OF RNA-POLYMERASE [J].
CHOY, HE ;
PARK, SW ;
AKI, T ;
PARRACK, P ;
FUJITA, N ;
ISHIHAMA, A ;
ADHYA, S .
EMBO JOURNAL, 1995, 14 (18) :4523-4529
[2]   TRANSCRIPTION CONTROL OF THE AROP GENE IN ESCHERICHIA-COLI K-12 - ANALYSIS OF OPERATOR MUTANTS [J].
CHYE, ML ;
PITTARD, J .
JOURNAL OF BACTERIOLOGY, 1987, 169 (01) :386-393
[3]   MOLECULAR MECHANISM OF NEGATIVE AUTOREGULATION OF ESCHERICHIA-COLI CRP GENE [J].
HANAMURA, A ;
AIBA, H .
NUCLEIC ACIDS RESEARCH, 1991, 19 (16) :4413-4419
[4]  
HERSHBERGER PA, 1993, J BIOL CHEM, V268, P8943
[5]   RNA-POLYMERASE BOUND TO THE PR PROMOTER OF BACTERIOPHAGE-LAMBDA INHIBITS OPEN COMPLEX-FORMATION AT THE DIVERGENTLY TRANSCRIBED-PRM PROMOTER - IMPLICATIONS FOR AN INDIRECT MECHANISM OF TRANSCRIPTIONAL ACTIVATION BY LAMBDA REPRESSOR [J].
HERSHBERGER, PA ;
DEHASETH, PL .
JOURNAL OF MOLECULAR BIOLOGY, 1991, 222 (03) :479-494
[6]  
KRAUSE HM, 1986, J BIOL CHEM, V261, P3744
[7]  
LIVRELLI V, 1993, J BIOL CHEM, V268, P2623
[8]  
Maxam A M, 1980, Methods Enzymol, V65, P499
[9]   Activation and repression of transcription at two different phage Phi 29 promoters are mediated by interaction of the same residues of regulatory protein p4 with RNA polymerase [J].
Monsalve, M ;
Mencia, M ;
Rojo, F ;
Salas, M .
EMBO JOURNAL, 1996, 15 (02) :383-391
[10]   MECHANISM FOR THE AUTOGENOUS CONTROL OF THE CRP OPERON - TRANSCRIPTIONAL INHIBITION BY A DIVERGENT RNA TRANSCRIPT [J].
OKAMOTO, K ;
FREUNDLICH, M .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1986, 83 (14) :5000-5004