Kukimoto-Niino Mutsuko, Ihara Kentaro, Mishima-Tsumagari Chiemi, Inoue Mio, Fukui Yoshinori, Yokoyama Shigeyuki, Shirouzu Mikako
Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan.
Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan.
Biochem Biophys Res Commun. 2023 Apr 23;653:12-20. doi: 10.1016/j.bbrc.2023.02.054. Epub 2023 Feb 21.
Dedicator of cytokinesis 10 (DOCK10), an evolutionarily conserved guanine nucleotide exchange factor (GEF) for Rho GTPases, has the unique specificity within the DOCK-D subfamily to activate both Cdc42 and Rac, but the structural bases for these activities remained unknown. Here we present the crystal structures of the catalytic DHR2 domain of mouse DOCK10, complexed with either Cdc42 or Rac1. The structures revealed that DOCK10 binds to Cdc42 or Rac1 by slightly changing the arrangement of its two catalytic lobes. DOCK10 also has a flexible binding pocket for the 56th GTPase residue, allowing a novel interaction with Trp56. The conserved residues in switch 1 of Cdc42 and Rac1 showed common interactions with the unique Lys-His sequence in the β5/β6 loop of DOCK10. However, the interaction of switch 1 in Rac1 was less stable than that of switch 1 in Cdc42, due to amino acid differences at positions 27 and 30. Structure-based mutagenesis identified the DOCK10 residues that determine the Cdc42/Rac1 dual specificity.
胞质分裂 dedicator 10（DOCK10）是一种Rho GTP酶的进化保守鸟嘌呤核苷酸交换因子（GEF），在DOCK-D亚家族中具有独特的特异性，可激活Cdc42和Rac，但这些活性的结构基础尚不清楚。在此，我们展示了与Cdc42或Rac1复合的小鼠DOCK10催化DHR2结构域的晶体结构。结构显示，DOCK10通过略微改变其两个催化叶的排列与Cdc42或Rac1结合。DOCK10还具有一个针对第56位GTP酶残基的灵活结合口袋，允许与Trp56进行新型相互作用。Cdc42和Rac1开关1中的保守残基与DOCK10的β5/β6环中独特的Lys-His序列表现出共同的相互作用。然而，由于27位和30位的氨基酸差异，Rac1中开关1的相互作用比Cdc42中开关1的相互作用更不稳定。基于结构的诱变确定了决定Cdc42/Rac1双重特异性的DOCK10残基。
