期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2016
卷号：113
期号：44
页码：12490-12495
DOI：10.1073/pnas.1602380113
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Despite their relative simplicity, bacteria have complex anatomy at the subcellular level. At the cell poles of Caulobacter crescentus, a 177-amino acid (aa) protein called PopZ self-assembles into 3D polymeric superstructures. Remarkably, we find that this assemblage interacts directly with at least eight different proteins, which are involved in cell cycle regulation and chromosome segregation. The binding determinants within PopZ include 24 aa at the N terminus, a 32-aa region near the C-terminal homo-oligomeric assembly domain, and portions of an intervening linker region. Together, the N-terminal 133 aa of PopZ are sufficient for interacting with all binding partners, even in the absence of homo-oligomeric assembly. Structural analysis of this region revealed that it is intrinsically disordered, similar to p53 and other hub proteins that organize complex signaling networks in eukaryotic cells. Through live-cell photobleaching, we find rapid binding kinetics between PopZ and its partners, suggesting many pole-localized proteins become concentrated at cell poles through rapid cycles of binding and unbinding within the PopZ scaffold. We conclude that some bacteria, similar to their eukaryotic counterparts, use intrinsically disordered hub proteins for network assembly and subcellular organization.
关键词：PopZ ; intrinsically disordered protein ; bacteria ; Caulobacter ; hub protein
