The CGL2612 protein from Corynebacterium glutamicum is a drug resistance-related transcriptional repressor: structural and functional analysis of a newly identified transcription factor from genomic DNA analysis.
The emergence of antibiotic-resistant bacteria often causes serious clinical problems. The TetR family is one of the major transcription factor families that regulate expression of genes involved in bacterial antimicrobial resistance systems. CGL2612 protein is a transcription factor newly identified by genomic DNA analysis on Corynebacterium glutamicum, which belongs to the mycolic acid-containing Actinomycetales, including the well known pathogens Corynebacterium diphtheriae and Mycobacterium tuberculosis. Crystal structure analysis showed that the CGL2612 protein exhibits significant structural similarity to the multidrug resistance (MDR)-related transcription factor QacR from Staphylococcus aureus, despite poor amino acid sequence similarity between these proteins. Binding DNA sequence analysis of CGL2612 protein using the systematic evolution of ligands by the exponential enrichment (systematic evolution of ligands by exponential enrichment, or SELEX) method revealed that this protein is a new member of the TetR family, which regulates expression of the immediately upstream gene, cgl2611, probably encoding a major facilitator superfamily permease. Subsequent functional analyses confirmed a function of the CGL2612 as a transcriptional repressor responsible for the antimicrobial resistance system in C. glutamicum. The strategy used in the present study is one of the most convenient and powerful methods to analyze functionally unknown transcription factors, and the results obtained here will contribute to our understanding of the drug resistance mechanism not only in C. glutamicum but also in the related bacteria, C. diphtheriae and M. tuberculosis.
Itou
Hiroshi
H
Division of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan.
Okada
Ui
U
Suzuki
Hiroaki
H
Yao
Min
M
Wachi
Masaaki
M
Watanabe
Nobuhisa
N
Tanaka
Isao
I
D000595:Amino Acid Sequence; D000890:Anti-Infective Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D048230:Corynebacterium glutamicum / Q000378:metabolism*; D018360:Crystallography, X-Ray; D004247:DNA / Q000378:metabolism; D017931:DNA Primers / Q000737:chemistry; D018076:DNA, Complementary / Q000737:chemistry / Q000378:metabolism; D003850:Deoxyribonuclease I / Q000737:chemistry / Q000378:metabolism; D019281:Dimerization; D024881:Drug Resistance, Bacterial; D018432:Drug Resistance, Multiple; D016680:Genome, Bacterial; D008024:Ligands; D008958:Models, Molecular; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D011485:Protein Binding; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins / Q000737:chemistry / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
D000890:Anti-Infective Agents; D001426:Bacterial Proteins; C506780:CGL2612 protein, Corynebacterium glutamicum; D017931:DNA Primers; D018076:DNA, Complementary; D008024:Ligands; D012097:Repressor Proteins; D004247:DNA; D003850:Deoxyribonuclease I