Mta, a global MerR-type regulator of the Bacillus subtilis multidrug-efflux transporters

Autor: Antoine Danchin, Natalya N. Baranova, Alexander A. Neyfakh
Rok vydání: 1999
Předmět:
Genotype
Transcription
Genetic
DNA Mutational Analysis
Molecular Sequence Data
DNA Footprinting
Regulator
ATP-binding cassette transporter
Bacillus subtilis
Microbiology
Bacterial Proteins
Acetyltransferases
Transduction
Genetic
Sequence Homology
Nucleic Acid
Genes
Regulator
Transcriptional regulation
ATP Binding Cassette Transporter
Subfamily B
Member 1
Amino Acid Sequence
Promoter Regions
Genetic
Molecular Biology
Regulation of gene expression
Sequence Homology
Amino Acid
biology
Membrane transport protein
Chromosome Mapping
Membrane Transport Proteins
Promoter
Gene Expression Regulation
Bacterial
Blotting
Northern
biology.organism_classification
Thiostrepton
Anti-Bacterial Agents
DNA-Binding Proteins
Membrane protein
Biochemistry
Multigene Family
Trans-Activators
biology.protein
Carrier Proteins
Zdroj: Molecular Microbiology. 31:1549-1559
ISSN: 1365-2958
0950-382X
DOI: 10.1046/j.1365-2958.1999.01301.x
Popis: Little is known about the natural functions of multidrug-efflux transporters expressed by bacteria. Although identified as membrane proteins actively extruding exogenous toxins from the cell, they may actually be involved in the transport of as yet unidentified specific natural substrates. The expression of two highly similar multidrug transporters of Bacillus subtilis, Bmr and Blt, is regulated by specific transcriptional activators, BmrR and BltR, respectively, which respond to different inducer molecules, thus suggesting distinct functions for the two transporters. Here, we describe an alternative mechanism of regulation, which involves a global transcriptional activator, Mta, a member of the MerR family of bacterial regulatory proteins. The individually expressed N-terminal DNA-binding domain of Mta interacts directly with the promoters of bmr and blt and induces transcription of these genes. Additionally, this domain stimulates the expression of the mta gene itself and at least one more gene, ydfK, which encodes a hypothetical membrane protein. These results and the similarity of Mta to the thiostrepton-induced protein TipA of Streptomyces lividans strongly suggest that Mta is an autogenously controlled global transcriptional regulator, whose activity is stimulated by an as yet unidentified inducer. This stimulation is mimicked by the removal of the C-terminal inducer-binding domain. The fact that both Bmr and Blt are controlled by this regulator demonstrates that some of their functions are either identical or, at least, related. Further analysis of Mta-mediated regulation may reveal the natural function of the system of multidrug transporters in B. subtilis and serve as a paradigm for similar systems in other bacteria.
Databáze: OpenAIRE
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