National Centre for Cell Science, University of Pune Campus, Pune, India.
Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, India.
FEBS Lett. 2020 Oct;594(20):3305-3323. doi: 10.1002/1873-3468.13906. Epub 2020 Sep 16.
Among the two GroEL paralogs in Mycobacterium tuberculosis, GroEL1 and GroEL2, GroEL1 has a characteristic histidine-rich C terminus. Since histidine richness is likely to be involved in metal binding, we attempted to decipher the role of GroEL1 in chelating metals and the consequence on M. tuberculosis physiology. Isothermal titration calorimetry showed that GroEL1 binds copper and other metals. Mycobacterial viability assay, redox balance, and DNA protection assay concluded that GroEL1 protects from copper stress in vitro. Solution X-ray scattering and constrained modeling of GroEL1 -/+ copper ions showed reorientation of the apical domain as seen in functional assembly. We conclude that the duplication of chaperonin genes in M. tuberculosis might have led to their evolutionary divergence and consequent functional divergence of chaperonins.
在结核分枝杆菌的两个 GroEL 同源物（GroEL1 和 GroEL2）中，GroEL1 具有特征性的富含组氨酸的 C 末端。由于组氨酸丰富度可能参与金属结合，我们试图破译 GroEL1 在螯合金属中的作用及其对结核分枝杆菌生理的影响。等温滴定量热法显示 GroEL1 结合铜和其他金属。体外细菌活力测定、氧化还原平衡和 DNA 保护测定表明 GroEL1 可抵抗铜胁迫。溶液 X 射线散射和 GroEL1-/+铜离子的约束建模显示，正如在功能组装中所见，顶端结构域发生了重定向。我们得出结论，结核分枝杆菌中分子伴侣基因的复制可能导致了它们的进化分歧和随后的分子伴侣功能的分歧。
