Tracking Ca²⁺ ATPase intermediates in real time by x-ray solution scattering.

ABSTRACT: Sarco/endoplasmic reticulum Ca²⁺ ATPase (SERCA) transporters regulate calcium signaling by active calcium ion reuptake to internal stores. Structural transitions associated with transport have been characterized by x-ray crystallography, but critical intermediates involved in the accessibility switch across the membrane are missing. We combined time-resolved x-ray solution scattering (TR-XSS) experiments and molecular dynamics (MD) simulations for real-time tracking of concerted SERCA reaction cycle dynamics in the native membrane. The equilibrium [Ca₂]E1 state before laser activation differed in the domain arrangement compared with crystal structures, and following laser-induced release of caged ATP, a 1.5-ms intermediate was formed that showed closure of the cytopla

SUBMITTER: Ravishankar H 

PROVIDER: S-EPMC7083613 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature