Cryo-EM structure of substrate-free E. coliLon protease provides insights into the dynamics of Lon machinery

Autor: Botos, Istvan, Lountos, George T., Wu, Weimin, Cherry, Scott, Ghirlando, Rodolfo, Kudzhaev, Arsen M., Rotanova, Tatyana V., de Val, Natalia, Tropea, Joseph E., Gustchina, Alla, Wlodawer, Alexander
Zdroj: Current Research in Structural Biology; November 2019, Vol. 1 Issue: 1 p13-20, 8p
Abstrakt: Energy-dependent Lon proteases play a key role in cellular regulation by degrading short-lived regulatory proteins and misfolded proteins in the cell. The structure of the catalytically inactive S679A mutant of Escherichia coliLonA protease (EcLon) has been determined by cryo-EM at the resolution of 3.5 Å. EcLonA without a bound substrate adopts a hexameric open-spiral quaternary structure that might represent the resting state of the enzyme. Upon interaction with substrate the open-spiral hexamer undergoes a major conformational change resulting in a compact, closed-circle hexamer as in the recent structure of a complex of Yersinia pestisLonA with a protein substrate. This major change is accomplished by the rigid-body rearrangement of the individual domains within the protomers of the complex around the hinge points in the interdomain linkers. Comparison of substrate-free and substrate-bound Lon structures allows to mark the location of putative pivotal points involved in such conformational changes.
Databáze: Supplemental Index