Molecular basis for curvature formation in SepF polymerization

• 成果类型: Article
• 署名作者: Liu, Wenjing; Zhang, Chang; Zhang, Huawei; Ma, Shaojie; Deng, Jing; Wang, Daping; Chang, Ziwei; Yang, Jun
• 署名单位: Chinese Academy of Sciences; Innovation Academy for Precision Measurement Science & Technology, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Chinese Academy of Sciences; Shenzhen Institute of Advanced Technology, CAS; Southern University of Science & Technology; Shenzhen University; Wuhan University of Science & Technology
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-9831
• DOI: 10.1073/pnas.2316922121
• 发表日期: 2024-02-27
• 关键词: structural basis; maintenance; principles; proteins; DYNAMICS; vipp1; fold; pspa

摘要

The self- assembly of proteins into curved structures plays an important role in many cellular processes. One good example of this phenomenon is observed in the septum- forming protein (SepF), which forms polymerized structures with uniform curvatures. SepF is essential for regulating the thickness of the septum during bacteria cell division. In Bacillus subtilis, SepF polymerization involves two distinct interfaces, the (3-(3 and alpha-alpha interfaces, which define the assembly unit and contact interfaces, respectively. However, the mechanism of curvature formation in this step is not yet fully understood. In this study, we employed solid - state NMR (SSNMR) to compare the structures of cyclic wild - type SepF assemblies with linear assemblies resulting from a mutation of G137 on the (3-(3 interface. Our results demonstrate that while the sequence differences arise from the internal assembly unit, the dramatic changes in the shape of the assemblies depend on the alpha-alpha interface between the units. We further provide atomic - level insights into how the angular variation of the alpha 2 helix on the alpha-alpha interface affects the curvature of the assemblies, using a combination of SSNMR, cryo- electron microscopy, and simulation methods. Our findings shed light on the shape control of protein assemblies and emphasize the importance of interhelical contacts in retaining curvature.