著者
Akihiko Nakamura Kei-ichi Okazaki Tadaomi Furuta Minoru Sakurai Jun Ando Ryota Iino
出版者
The Biophysical Society of Japan
雑誌
Biophysics and Physicobiology (ISSN:21894779)
巻号頁・発行日
vol.17, pp.51-58, 2020 (Released:2020-07-10)
参考文献数
26

Motor proteins are essential units of life and are well-designed nanomachines working under thermal fluctuations. These proteins control moving direction by consuming chemical energy or by dissipating electrochemical potentials. Chitinase A from bacterium Serratia marcescens (SmChiA) processively moves along crystalline chitin by hydrolysis of a single polymer chain to soluble chitobiose. Recently, we directly observed the stepping motions of SmChiA labeled with a gold nanoparticle by dark-field scattering imaging to investigate the moving mechanism. Time constants analysis revealed that SmChiA moves back and forth along the chain freely, because forward and backward states have a similar free energy level. The similar probabilities of forward-step events (83.5%=69.3%+14.2%) from distributions of step sizes and chain-hydrolysis (86.3%=(1/2.9)/(1/2.9+1/18.3)×100) calculated from the ratios of time constants of hydrolysis and the backward step indicated that SmChiA moves forward as a result of shortening of the chain by a chitobiose unit, which stabilizes the backward state. Furthermore, X-ray crystal structures of sliding intermediate and molecular dynamics simulations showed that SmChiA slides forward and backward under thermal fluctuation without large conformational changes of the protein. Our results demonstrate that SmChiA is a burnt-bridge Brownian ratchet motor.

言及状況

外部データベース (DOI)

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Ranked 1st of the most viewed articles Aug. 2020! https://t.co/z6PDkExuZz Review Article: Crystalline chitin hydrolase is a burnt-bridge Brownian motor https://t.co/1Hp32f5gSR
Ranked 1st of the Most viewed articles Jul 2020! Thank you so much! https://t.co/z6PDkExuZz Crystalline chitin hydrolase is a burnt-bridge Brownian motor https://t.co/cRGU1GntR4 https://t.co/BWhQRUUBCt
Akihiko's review article has been featured on the cover of Biophysics and Physicobiology, the official journal of The Biophysical Society of Japan! https://t.co/AqK3QnBdDA https://t.co/1Hp32f5gSR https://t.co/hVFCtWAIFx
Akihiko's review article now has been published officially in BPPB! Open access! Crystalline chitin hydrolase is a burnt-bridge Brownian motor https://t.co/8juALJde7f https://t.co/WSRxAXeCXl

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