TY  - JOUR
A1  - Bhat, Javaid Y.
A1  - Milicic, Goran
A1  - Thieulin-Pardo, Gabriel
A1  - Bracher, Andreas
A1  - Maxwell, Andrew
A1  - Ciniawsky, Susanne
A1  - Müller-Cajar, Oliver
A1  - Engen, John R.
A1  - Hartl, F. Ulrich
A1  - Wendler, Petra
A1  - Hayer-Hartl, Manajit
T1  - Mechanism of Enzyme Repair by the AAA(+) Chaperone Rubisco Activase
JF  - Molecular cell
N2  - How AAA(+) chaperones conformationally remodel specific target proteins in an ATP-dependent manner is not well understood. Here, we investigated the mechanism of the AAA(+) protein Rubisco activase (Rca) in metabolic repair of the photosynthetic enzyme Rubisco, a complex of eight large (RbcL) and eight small (RbcS) subunits containing eight catalytic sites. Rubisco is prone to inhibition by tight-binding sugar phosphates, whose removal is catalyzed by Rca. We engineered a stable Rca hexamer ring and analyzed its functional interaction with Rubisco. Hydrogen/deuterium exchange and chemical crosslinking showed that Rca structurally destabilizes elements of the Rubisco active site with remarkable selectivity. Cryo-electron microscopy revealed that Rca docks onto Rubisco over one active site at a time, positioning the C-terminal strand of RbcL, which stabilizes the catalytic center, for access to the Rca hexamer pore. The pulling force of Rca is fine-tuned to avoid global destabilization and allow for precise enzyme repair.
Y1  - 2017
U6  - https://doi.org/10.1016/j.molcel.2017.07.004
SN  - 1097-2765
SN  - 1097-4164
VL  - 67
SP  - 744
EP  - 756
PB  - Cell Press
CY  - Cambridge
ER  -