Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
Graduate School of Informatics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
Acta Crystallogr F Struct Biol Commun. 2021 Jan 1;77(Pt 1):13-21. doi: 10.1107/S2053230X20016829.
V-1, also known as myotrophin, is a 13 kDa ankyrin-repeat protein that binds and inhibits the heterodimeric actin capping protein (CP), which is a key regulator of cytoskeletal actin dynamics. The crystal structure of V-1 in complex with CP revealed that V-1 recognizes CP via residues spanning several ankyrin repeats. Here, the crystal structure of human V-1 is reported in the absence of the specific ligand at 2.3 Å resolution. In the asymmetric unit, the crystal contains two V-1 monomers that exhibit nearly identical structures (C r.m.s.d. of 0.47 Å). The overall structures of the two apo V-1 chains are also highly similar to that of CP-bound V-1 (C r.m.s.d.s of <0.50 Å), indicating that CP does not induce a large conformational change in V-1. Detailed structural comparisons using the computational program All Atom Motion Tree revealed that CP binding can be accomplished by minor side-chain rearrangements of several residues. These findings are consistent with the known biological role of V-1, in which it globally inhibits CP in the cytoplasm.
V-1，也被称为肌萎缩蛋白，是一种 13 kDa 的锚蛋白重复蛋白，它可以结合并抑制异二聚体肌动蛋白加帽蛋白（CP），CP 是细胞骨架肌动蛋白动力学的关键调节剂。V-1 与 CP 复合物的晶体结构揭示了 V-1 通过跨越几个锚蛋白重复的残基来识别 CP。在此，报道了在 2.3 Å 分辨率下无特定配体的人源 V-1 的晶体结构。在不对称单元中，晶体包含两个 V-1 单体，它们具有几乎相同的结构（C r.m.s.d. 为 0.47 Å）。两个apo V-1 链的整体结构也与 CP 结合的 V-1 非常相似（C r.m.s.d.s 小于 0.50 Å），这表明 CP 不会在 V-1 中诱导大的构象变化。使用计算程序 All Atom Motion Tree 进行的详细结构比较表明，CP 结合可以通过几个残基的侧链小的重排来完成。这些发现与 V-1 的已知生物学作用一致，即它在细胞质中全局抑制 CP。
