小柯机器人

浙江大学郭江涛等研究人员合作揭示拟南芥生长素转运蛋白PIN3的结构和机制。这一研究成果于2022年8月2日在线发表在国际学术期刊《自然》上。

研究人员以2.6-3.0 Å的分辨率展示了拟南芥PIN3（AtPIN3）在apo状态下及其与底物吲哚-3-乙酸（IAA）和抑制剂N-1-naphthylphthalamic acid（NPA）的复合物冷冻电镜结构。AtPIN3以同源二聚体的形式存在，支架结构域中的跨膜螺旋（TM）1、2和7参与了二聚化。二聚体AtPIN3在二聚体界面上形成了一个大的、联合的面向细胞外的空腔，而每个亚单位都采取了一个面向内的构象。

结构和功能分析以及计算研究揭示了识别IAA和NPA的结构基础，并阐明了NPA对PIN介导的生长素转运分子机制。AtPIN3的结构支持一个类似电梯的生长素运输模型，即运输结构域进行上下的刚体运动，而二聚体支架结构域保持静止。

据悉，生长素转运体的PIN-FORMED（PIN）家族介导极性辅酶的转运，在植物生长和发育中起着关键作用。

附：英文原文

Title: Structures and mechanisms of the Arabidopsis auxin transporter PIN3

Author: Su, Nannan, Zhu, Aiqin, Tao, Xin, Ding, Zhong Jie, Chang, Shenghai, Ye, Fan, Zhang, Yan, Zhao, Cheng, Chen, Qian, Wang, Jiangqin, Zhou, Chen Yu, Guo, Yirong, Jiao, Shasha, Zhang, Sufen, Wen, Han, Ma, Lixin, Ye, Sheng, Zheng, Shao Jian, Yang, Fan, Wu, Shan, Guo, Jiangtao

Issue&Volume: 2022-08-02

Abstract: The PIN-FORMED (PIN) protein family of auxin transporters mediates the polar auxin transport and plays crucial roles in plant growth and development1,2. Here we present cryo-EM structures of PIN3 from Arabidopsis thaliana (AtPIN3) in the apo state and in complex with its substrate indole-3-acetic acid (IAA) and the inhibitor N-1-naphthylphthalamic acid (NPA) at 2.6–3.0 resolution. AtPIN3 exists as a homodimer, with the transmembrane helices (TMs) 1, 2, and 7 in the scaffold domain involved in dimerization. The dimeric AtPIN3 forms a large, joint extracellular-facing cavity at the dimer interface while each subunit adopts an inward-facing conformation. The structural and functional analyses, along with computational studies, reveal the structural basis for the recognition of IAA and NPA and elucidate the molecular mechanism of NPA inhibition on the PIN-mediated auxin transport. The AtPIN3 structures support an elevator-like model for the transport of auxin, whereby the transport domains undergo up-down rigid-body motions and the dimerized scaffold domains remain static.

DOI: 10.1038/s41586-022-05142-w

Source: https://www.nature.com/articles/s41586-022-05142-w

Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
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