Cloning and characterization of SmeT, a repressor of the Stenotrophomonas maltophilia multidrug efflux pump SmeDEF

被引:71
作者
Sánchez, P [1 ]
Alonso, A [1 ]
Martinez, JL [1 ]
机构
[1] CSIC, Ctr Nacl Biotecnol, Dept Biotecnol Microbiana, Madrid 28049, Spain
关键词
D O I
10.1128/AAC.46.11.3386-3393.2002
中图分类号
Q93 [微生物学];
学科分类号
071005 ; 100705 ;
摘要
We report on the cloning of the gene smeT, which encodes the transcriptional regulator of the Stenotrophomonas maltophilia efflux pump SmeDEF. SmeT belongs to the TetR and AcrR family of transcriptional regulators. The smeT gene is located upstream from the structural operon of the pump genes smeDEF and is divergently transcribed from those genes. Experiments with S. maltophilia and the heterologous host Escherichia coli have demonstrated that SmeT is a transcriptional repressor. S1 nuclease mapping has demonstrated that expression of smeT is driven by a single promoter lying close to the 5' end of the gene and that expression of smeDEF is driven by an unique promoter that overlaps with promoter PsmeT. The level of expression of smeT is higher in smeDEF-overproducing S. maltophilia strain D457R, which suggests that SmeT represses its own expression. Band-shifting assays have shown that wild-type strain S. maltophilia D457 contains a cellular factor(s) capable of binding to the intergenic smeT-smeD region. That cellular factor(s) was absent from smeDEF-overproducing S. maltophilia strain D457R. The sequence of. smeT from D457R showed a point mutation that led to a Leu166Gln change within the SmeT protein. This change allowed overexpression of both smeDEF and smeT in D457R. It was noteworthy that expression of wild-type SmeT did not fully complement the smeT mutation in D457R. This suggests that the wild-type protein is not dominant over the mutant SmeT.
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页码:3386 / 3393
页数:8
相关论文
共 43 条
[1]   Cloning and characterization of SmeDEF, a novel multidrug efflux pump from Stenotrophomonas maltophilia [J].
Alonso, A ;
Martínez, JL .
ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, 2000, 44 (11) :3079-3086
[2]   Stenotrophomonas maltophilia D457R contains a cluster of genes from gram-positive bacteria involved in antibiotic and heavy metal resistance [J].
Alonso, A ;
Sanchez, P ;
Martínez, JL .
ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, 2000, 44 (07) :1778-1782
[3]   Multiple antibiotic resistance in Stenotrophomonas maltophilia [J].
Alonso, A ;
Martinez, JL .
ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, 1997, 41 (05) :1140-1142
[4]   Expression of multidrug efflux pump SmeDEF by clinical isolates of Stenotrophomonas maltophilia [J].
Alonso, A ;
Martinez, JL .
ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, 2001, 45 (06) :1879-1881
[5]  
[Anonymous], 1983, COLD SPRING HARBOR L
[6]  
Atlas R. M., 1993, HDB MICROBIOLOGICAL
[7]   FUNCTIONAL ROLES OF AMINO-ACID-RESIDUES INVOLVED IN FORMING THE ALPHA-HELIX-TURN-ALPHA-HELIX OPERATOR DNA-BINDING MOTIF OF TET REPRESSOR FROM TN10 [J].
BAUMEISTER, R ;
MULLER, G ;
HECHT, B ;
HILLEN, W .
PROTEINS-STRUCTURE FUNCTION AND GENETICS, 1992, 14 (02) :168-177
[8]   DELETION MUTAGENESIS OF TN10 TET REPRESSOR - LOCALIZATION OF REGIONS IMPORTANT FOR DIMERIZATION AND INDUCIBILITY IN-VIVO [J].
BERENS, C ;
PFLEIDERER, K ;
HELBL, V ;
HILLEN, W .
MOLECULAR MICROBIOLOGY, 1995, 18 (03) :437-448
[9]   The complete genome sequence of Escherichia coli K-12 [J].
Blattner, FR ;
Plunkett, G ;
Bloch, CA ;
Perna, NT ;
Burland, V ;
Riley, M ;
ColladoVides, J ;
Glasner, JD ;
Rode, CK ;
Mayhew, GF ;
Gregor, J ;
Davis, NW ;
Kirkpatrick, HA ;
Goeden, MA ;
Rose, DJ ;
Mau, B ;
Shao, Y .
SCIENCE, 1997, 277 (5331) :1453-+
[10]   Role of the alternative sigma factor σS in expression of the AlkS regulator of the Pseudomonas oleovorans alkane degradation pathway [J].
Canosa, I ;
Yuste, L ;
Rojo, F .
JOURNAL OF BACTERIOLOGY, 1999, 181 (06) :1748-1754