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Updated: Aug 11, 2026
Testing the Role of Multicopy Plasmids in the Evolution of Antibiotic Resistance
Published on: May 2, 2018
Cloning, expression, crystallization and preliminary X-ray analysis of a putative multiple antibiotic resistance
Zhi-Le Tu1, Juo-Ning Li, Ko-Hsin Chin
1Institute of Biochemistry, National Chung-Hsing University, Taichung 40227, Taiwan.
Abstract:
The multiple antibiotic resistance operon (marRAB) is a member of the multidrug-resistance system. When induced, this operon enhances resistance of bacteria to a variety of medically important antibiotics, causing a serious global health problem. MarR is a marR-encoded protein that represses the transcription of the marRAB operon. Through binding with salicylate and certain antibiotics, however, MarR can derepress and activate the marRAB operon. In this report, the cloning, expression, crystallization and preliminary X-ray analysis of XC1739, a putative MarR repressor protein present in the Xanthomonas campestris pv. campestris, a Gram-negative bacterium causing major worldwide disease of cruciferous crops, are described. The XC1739 crystals diffracted to a resolution of at least 1.8 A. They are orthorhombic and belong to space group P2(1)2(1)2(1), with unit-cell parameters a = 39.5, b = 54.2 and c = 139.5 A, respectively. They contain two molecules in the asymmetric unit from calculation of the self-rotation function.
Insights
Researchers crystallized XC1739, a MarR repressor protein from Xanthomonas campestris pv. campestris. This protein regulates bacterial antibiotic resistance, a critical global health concern.
Area of Science:
- Microbiology
- Structural Biology
- Biochemistry
Background:
- The multiple antibiotic resistance operon (marRAB) confers bacterial resistance to antibiotics, contributing to a global health crisis.
- MarR repressor proteins regulate the marRAB operon, responding to environmental signals like salicylate and antibiotics.
Purpose of the Study:
- To characterize XC1739, a putative MarR repressor from Xanthomonas campestris pv. campestris, a plant pathogen.
- To determine the crystal structure of XC1739 for insights into its regulatory mechanism.
Main Methods:
- Cloning and expression of the XC1739 gene.
- Crystallization of the XC1739 protein.
- Preliminary X-ray diffraction analysis of XC1739 crystals.
Main Results:
- XC1739 crystals were obtained and diffracted to 1.8 A resolution.
- The crystals belong to the orthorhombic space group P2(1)2(1)2(1).
- The asymmetric unit contains two XC1739 molecules.
Conclusions:
- The structural characterization of XC1739 provides a foundation for understanding multidrug resistance regulation in Xanthomonas.
- This work contributes to efforts to combat antibiotic resistance in bacterial pathogens.
