how to change the oligomeric state of a circular protein assembly switch from 11-subunit to 12-subunit trap suggests a general mechanism如何改变一个圆形的低聚物的状态蛋白装配开关从11-subunit 12-subunit陷阱提出一个通用的机制.pdfVIP

How to Change the Oligomeric State of a Circular Protein Assembly: Switch from 11-Subunit to 12-Subunit TRAP Suggests a General Mechanism 1 1 1 1,2 3 Chao-Sheng Chen , Callum Smits , Guy G. Dodson , Mikhail B. Shevtsov , Natalie Merlino , Paul Gollnick3, Alfred A. Antson 1* 1 York Structural Biology Laboratory, Department of Chemistry, University of York, York, United Kingdom, 2 Biological Sciences, University of Portsmouth, King Henry Building, Portsmouth, United Kingdom, 3 Department of Biological Sciences, State University of New York at Buffalo, Buffalo, New York, United States of America Abstract Background: Many critical cellular functions are performed by multisubunit circular protein oligomers whose internal geometry has evolved to meet functional requirements. The subunit number is arguably the most critical parameter of a circular protein assembly, affecting the internal and external diameters of the assembly and often impacting on the protein’s function. Although accurate structural information has been obtained for several circular proteins, a lack of accurate information on alternative oligomeric states has prevented engineering such transitions. In this study we used the bacterial transcription regulator TRAP as a model system to investigate the features that define the oligomeric state of a circular protein and to question how the subunit number could be manipulated. Methodology/Principal Findings: We find that while Bacillus subtilis and Bacillus stearothermophilus TRAP form 11-su