Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi, India.
National Institute of Immunology, New Delhi, India.
J Biomol Struct Dyn. 2024 Aug;42(12):6189-6199. doi: 10.1080/07391102.2023.2232032. Epub 2023 Jul 7.
(), the causative agent of tuberculosis when infects the host encounters several stresses within the host, resulting in aggregation of its proteins. To resolve this problem uses chaperones to either repair the damage or degrade the aggregated proteins caseinolytic protein B (ClpB) helps in the prevention of aggregation and also resolubilization of aggregated proteins in bacteria, which is important for the survival of in the host. To function optimally, ClpB associates with its co-partners DnaK, DnaJ, and GrpE. The role of N-terminal domain (NTD) of ClpB in its function is not well understood. In this context, we investigated the interaction of three substrate mimicking peptides with the NTD of ClpB . A substrate binding pocket, within the NTD of ClpB comprising of residues L136, R137, E138, K142, R144, R148, V149, Y158, and Y162 forming an ɑ-helix was thus identified. The residues L136 and R137 of the ɑ-helix were found to be important for the interaction of DnaK to ClpB. Further, nine single alanine recombinant variants of the identified residues were generated. As compared to the wild-type ClpB all the ClpB variants generated in this study were found to have reduced ATPase and protein refolding activity indicating the importance of the substrate binding pocket in ClpB function. The study demonstrates that the NTD of ClpB is important for its substrate interaction activity, and the substrate binding pocket identified in this study plays a crucial role in this interaction.Communicated by Ramaswamy H. Sarma.
（），结核病的病原体，当它感染宿主时，会在宿主体内遇到几种应激，导致其蛋白质聚集。为了解决这个问题，使用伴侣蛋白来修复损伤或降解聚集的蛋白质。其中，蛋白酶体 B（ClpB）有助于防止细菌聚集，并使聚集的蛋白质重新溶解，这对于在宿主中生存非常重要。为了发挥最佳功能，ClpB 与它的共同伙伴 DnaK、DnaJ 和 GrpE 结合。ClpB 的 N 端结构域（NTD）在其功能中的作用尚不清楚。在这种情况下，我们研究了三种模拟底物的肽与 ClpB 的 NTD 的相互作用。一个位于 ClpB 的 NTD 内的底物结合口袋，由残基 L136、R137、E138、K142、R144、R148、V149、Y158 和 Y162 组成一个α-螺旋，从而被鉴定出来。α-螺旋中的残基 L136 和 R137 对于 DnaK 与 ClpB 的相互作用很重要。此外，还生成了 9 个识别出的残基的单个丙氨酸重组变体。与野生型 ClpB 相比，本研究中生成的所有 ClpB 变体的 ATPase 和蛋白质重折叠活性均降低，这表明底物结合口袋在 ClpB 功能中的重要性。该研究表明，ClpB 的 NTD 对于其底物相互作用活性很重要，并且本研究中鉴定的底物结合口袋在这种相互作用中起着关键作用。由 Ramaswamy H. Sarma 传达。
