The VapBC1 toxin-antitoxin complex from Mycobacterium tuberculosis: purification, crystallization and X-ray diffraction analysis.
Mycobacterium tuberculosis, a major human pathogen, encodes at least 88 toxin-antitoxin (TA) systems. Remarkably, more than half of these modules belong to the VapBC family. Under normal growth conditions, the toxicity of the toxin VapC is neutralized by the protein antitoxin VapB. When bacteria face an unfavourable environment, the antitoxin is degraded and the free toxin VapC targets important cellular processes in order to inhibit cell growth. TA systems function in many biological processes, such as in the stringent response, in biofilm formation and in drug tolerance. To explore the structure of the VapBC1 complex, the toxin VapC1 and the antitoxin VapB1 were separately cloned, co-expressed and crystallized. The best crystal was obtained using a crystallization solution consisting of optimized solution with commercial sparse-matrix screen solutions as additives. The crystal diffracted to a resolution of 2.7 Å and belonged to space group P21, with unit-cell parameters a = 59.3, b = 106.7, c = 250.0 Å, β = 93.75°.
College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin City 300071, People's Republic of China.
Zuokun
Z
Lu
College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin City 300071, People's Republic of China.
Han
H
Wang
College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin City 300071, People's Republic of China.
Aili
A
Zhang
School of Life Sciences, Tianjin University, Tianjin City, People's Republic of China.
Yusheng
Y
Tan
D000595:Amino Acid Sequence; D000992:Antitoxins / Q000737:chemistry*; D001426:Bacterial Proteins / Q000737:chemistry*; D001427:Bacterial Toxins / Q000737:chemistry*; D003460:Crystallization; D018360:Crystallography, X-Ray / Q000379:methods*; D009169:Mycobacterium tuberculosis / Q000737:chemistry*
D000992:Antitoxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins
Mycobacterium tuberculosis; VapBC; drug target; toxin–antitoxin system