The bacterial flagellar cap as the rotary promoter of flagellin

摘要

The body of a living being is constructed by the self-assembly of proteins produced in accordance with the translation of genome information. In many cases, a nano-machine is required to play an active role in promoting this self-assembly. And this nano-machine is also a self-assembled protein composite. The Namba Protonic Nano-Machine Project of the Creative Science and Technology Promotion Bureau at the Japan Science and Technology Corporation, while studying the structure and functions of a driving engine "flagellar motor" possessed by many bacteria for swimming and a slender, helical propeller "flagellar fiber" that is rotated at high speeds by that motor, has made clear for the first time the way in which when protein molecules called flagellins pile up on top of each other by self-assembly to form and grow flagella, a different protein composite having a constantly required structure called "cap" helps the growth of the flagella by rotating itself at the tips of the flagella in a dynamic fashion, which is worthy of being called a nano-machine.