Andrianova A G, Kudzhaev A M, Abrikosova V A, Gustchina A E, Smirnov I V, Rotanova T V
Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997 Russia.
Macromolecular Crystallography Laboratory, NCI-Frederick, P.O. Box B, Frederick, MD 21702, USA.
Acta Naturae. 2020 Oct-Dec;12(4):86-97. doi: 10.32607/actanaturae.11197.
ATP-dependent Lon protease of (Lon), which belongs to the superfamily of AAA proteins, is a key component of the cellular proteome quality control system. It is responsible for the cleavage of mutant, damaged, and short-lived regulatory proteins that are potentially dangerous for the cell. Lon functions as a homooligomer whose subunits contain a central characteristic AAA module, a C-terminal protease domain, and an N-terminal non-catalytic region composed of the actual N-terminal domain and the inserted α-helical domain. An analysis of the N domain crystal structure suggested a potential involvement of residues E34, K35, and R38 in the formation of stable and active Lon. We prepared and studied a triple mutant LonEKR in which these residues were replaced with alanine. The introduced substitutions were shown to affect the conformational stability and nucleotide-induced intercenter allosteric interactions, as well as the formation of the proper protein binding site.
属于AAA蛋白超家族的ATP依赖性Lon蛋白酶（Lon）是细胞蛋白质组质量控制系统的关键组成部分。它负责切割对细胞有潜在危险的突变、受损和短命的调节蛋白。Lon作为一种同型寡聚体发挥作用，其亚基包含一个中央特征性AAA模块、一个C端蛋白酶结构域以及一个由实际N端结构域和插入的α螺旋结构域组成的N端非催化区域。对N结构域晶体结构的分析表明，E34、K35和R38残基可能参与稳定且有活性的Lon的形成。我们制备并研究了一个三联突变体LonEKR，其中这些残基被丙氨酸取代。结果表明，引入的取代会影响构象稳定性和核苷酸诱导的中心间变构相互作用，以及合适蛋白质结合位点的形成。
