Ionic strength‐dependent conformations of a ubiquitin‐like small archaeal modifier protein (SAMP1) from Haloferax volcanii
Ionic strength‐dependent conformations of a ubiquitin‐like small archaeal modifier protein (SAMP1) from Haloferax volcanii
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DOI：
10.1002/pro.2302
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发表时间：
2013-09
期刊：
影响因子：
8
通讯作者：
Kaiqin Ye;S. Liao;Wen Zhang;K. Fan;Xuecheng Zhang;Jiahai Zhang;Chao Xu;X. Tu
中科院分区：
文献类型：
--
作者：
Kaiqin Ye;S. Liao;Wen Zhang;K. Fan;Xuecheng Zhang;Jiahai Zhang;Chao Xu;X. Tu
真核泛素和泛素样系统在各种细胞生物过程中发挥着至关重要的作用。在这项工作中，我们通过核磁共振波谱确定了 Haloferax volcanii 中 SAMP1 的溶液结构。在低离子条件下，SAMP1呈现出两种不同的构象，一种是折叠的β-grasp，另一种是无序的。有趣的是，随着离子浓度的增加，SAMP1经历了从无序到有序的构象转变，表明有序构象是SAMP1在H. volcanii生理条件下的功能形式。此外，SAMP1 可以与蛋白酶体激活核苷酸酶 B 相互作用，假设 SAMP1 在蛋白酶体介导的蛋白质降解途径中具有潜在作用。
Eukaryotic ubiquitin and ubiquitin‐like systems play crucial roles in various cellular biological processes. In this work, we determined the solution structure of SAMP1 from Haloferax volcanii by NMR spectroscopy. Under low ionic conditions, SAMP1 presented two distinct conformations, one folded β‐grasp and the other disordered. Interestingly, SAMP1 underwent a conformational conversion from disorder to order with ion concentration increasing, indicating that the ordered conformation is the functional form of SAMP1 under the physiological condition of H. volcanii. Furthermore, SAMP1 could interact with proteasome‐activating nucleotidase B, supposing a potential role of SAMP1 in the protein degradation pathway mediated by proteasome.