Repression at a distance by the global regulator KorB of promiscuous IncP plasmids

被引:40
作者
Jagura-Burdzy, G
Macartney, DP
Zatyka, M
Cunliffe, L
Cooke, D
Huggins, C
Westblade, L
Khanim, F
Thomas, CM
机构
[1] Univ Birmingham, Sch Biol Sci, Birmingham B15 2TT, W Midlands, England
[2] Polish Acad Sci, Inst Biochem & Biophys, Dept Microbial Biochem, Warsaw, Poland
基金
英国惠康基金;
关键词
D O I
10.1046/j.1365-2958.1999.01365.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
KorB protein (358 amino acids) binds to 12 highly conserved sequences on the RK2 genome and co-ordinates the expression of at least five operons encoding genes for stable inheritance and plasmid transfer. KorB represses the trfA, korA and klaA promoters where it binds 4 bp upstream of the -35 region (class I KorB operators, O-B) We show here that KorB on its own can also repress the trbA, trbB, kfrA and kleA promoters where O-B is between 80 and 189 bp away from the transcription start point (class II operator). A C-terminal deletion of 17 amino acids resulted in the loss of KorB's ability to repress through class II operator but not through class I operator. This deletion reduced multimerization of His(6)-tailed KorB protein in vitro and greatly reduced binding specificity for fragments containing O-B sequences. At the trbBp region, where O(B)9 lies 189 bp upstream of the transcription start point, mutagenesis of a proposed secondary binding site overlapping the trbBp -35 region had no effect on the ability of KorB to repress trbB, Nevertheless, gel retardation analysis showed that KorB binding is promoted by sequences upstream and downstream of O(B)9 and that KorB can form higher order complexes on DNA. However, DNase I footprinting suggested that RNA polymerase may interact directly with KorB bound at O(B)9 and implied that contacts between these proteins could be responsible for the action of KorB at a distance.
引用
收藏
页码:519 / 532
页数:14
相关论文
共 45 条
[41]  
WILLIAMS DR, 1992, J GEN MICROBIOL, V138, P1
[42]   MULTIFUNCTIONAL REPRESSOR KORB CAN BLOCK TRANSCRIPTION BY PREVENTING ISOMERIZATION OF RNA-POLYMERASE PROMOTER COMPLEXES [J].
WILLIAMS, DR ;
MOTALLEBIVESHAREH, M ;
THOMAS, CM .
NUCLEIC ACIDS RESEARCH, 1993, 21 (05) :1141-1148
[43]   Transcriptional and translational control of the genes for the mating pair formation apparatus of promiscuous IncP plasmids [J].
Zatyka, M ;
Jagura-Burdzy, G ;
Thomas, CM .
JOURNAL OF BACTERIOLOGY, 1997, 179 (23) :7201-7209
[44]   REGULATION OF TRANSFER GENES OF PROMISCUOUS INCP-ALPHA PLASMID RK2 - REPRESSION OF TRA1 REGION TRANSCRIPTION BOTH BY RELAXOSOME PROTEINS AND BY THE TRA2 REGULATOR TRBA [J].
ZATYKA, M ;
JAGURA-BURDZY, G ;
THOMAS, CM .
MICROBIOLOGY-SGM, 1994, 140 :2981-2990
[45]   CHROMOGENIC IDENTIFICATION OF GENETIC REGULATORY SIGNALS IN BACILLUS-SUBTILIS BASED ON EXPRESSION OF A CLONED PSEUDOMONAS GENE [J].
ZUKOWSKI, MM ;
GAFFNEY, DF ;
SPECK, D ;
KAUFFMANN, M ;
FINDELI, A ;
WISECUP, A ;
LECOCQ, JP .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES, 1983, 80 (04) :1101-1105