The Crystal Structure of the Ca2+-ATPase 1 from Listeria monocytogenes reveals a Pump Primed for Dephosphorylation |
| |
Institution: | 1. Department of Molecular Biology and Genetics, Aarhus University, Denmark;2. The Danish Research Institute for Translational Neuroscience (DANDRITE), Nordic EMBL Partnership for Molecular Medicine, Denmark;3. Aarhus Institute of Advanced Studies (AIAS), Denmark;4. The Danish National Research Foundation Center for Proteins in Memory (PROMEMO), Denmark |
| |
Abstract: | Many bacteria export intracellular calcium using active transporters homologous to the sarco/endoplasmic reticulum Ca2+-ATPase (SERCA). Here we present three crystal structures of Ca2+-ATPase 1 from Listeria monocytogenes (LMCA1). Structures with BeF3- mimicking a phosphoenzyme state reveal a closed state, which is intermediate between the outward-open E2P and the proton-occluded E2-P* conformations known for SERCA. It suggests that LMCA1 in the E2P state is pre-organized for dephosphorylation upon Ca2+ release, consistent with the rapid dephosphorylation observed in single-molecule studies. An arginine side-chain occupies the position equivalent to calcium binding site I in SERCA, leaving a single Ca2+ binding site in LMCA1, corresponding to SERCA site II. Observing no putative transport pathways dedicated to protons, we infer a direct proton counter transport through the Ca2+ exchange pathways. The LMCA1 structures provide insight into the evolutionary divergence and conserved features of this important class of ion transporters. |
| |
Keywords: | Listeria calcium membrane protein crystallography P-type ATPase |
本文献已被 ScienceDirect 等数据库收录! |
|