4NAB

Structure of the (SR)Ca2+-ATPase mutant E309Q in the Ca2-E1-MgAMPPCP form

Summary for 4NAB

• Entry DOI: 10.2210/pdb4nab/pdb
• Related: 3N8G
• Descriptor: Sarcoplasmic/endoplasmic reticulum calcium ATPase 1, CALCIUM ION, 1,2-DIOLEOYL-SN-GLYCERO-3-PHOSPHOCHOLINE, ... (5 entities in total)
• Functional Keywords: mutant e309q, p-type atpase, calcium-transporting atpase, sarcoplasmic reticulum, hydrolase
• Biological source: Oryctolagus cuniculus (European rabbit,Japanese white rabbit,domestic rabbit,rabbits)
• Cellular location: Endoplasmic reticulum membrane ; Multi-pass membrane protein : P04191
• Total number of polymer chains: 1
• Total formula weight: 111088.68

Authors

Bublitz, M.,Clausen, J.D.,Arnou, B.,Montigny, C.,Jaxel, C.,Nissen, P.,Moller, J.V.,Andersen, J.P.,le Maire, M. (deposition date: 2013-10-22, release date: 2013-12-18, Last modification date: 2024-11-20)

Primary citation

Clausen, J.D.,Bublitz, M.,Arnou, B.,Montigny, C.,Jaxel, C.,Moller, J.V.,Nissen, P.,Andersen, J.P.,le Maire, M.
SERCA mutant E309Q binds two Ca(2+) ions but adopts a catalytically incompetent conformation.
Embo J., 32:3231-3243, 2013

PubMed Abstract: The sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) couples ATP hydrolysis to transport of Ca(2+). This directed energy transfer requires cross-talk between the two Ca(2+) sites and the phosphorylation site over 50 Å distance. We have addressed the mechano-structural basis for this intramolecular signal by analysing the structure and the functional properties of SERCA mutant E309Q. Glu(309) contributes to Ca(2+) coordination at site II, and a consensus has been that E309Q only binds Ca(2+) at site I. The crystal structure of E309Q in the presence of Ca(2+) and an ATP analogue, however, reveals two occupied Ca(2+) sites of a non-catalytic Ca2E1 state. Ca(2+) is bound with micromolar affinity by both Ca(2+) sites in E309Q, but without cooperativity. The Ca(2+)-bound mutant does phosphorylate from ATP, but at a very low maximal rate. Phosphorylation depends on the correct positioning of the A-domain, requiring a shift of transmembrane segment M1 into an 'up and kinked position'. This transition is impaired in the E309Q mutant, most likely due to a lack of charge neutralization and altered hydrogen binding capacities at Ca(2+) site II.

PubMed: 24270570
DOI: 10.1038/emboj.2013.250

Experimental method

X-RAY DIFFRACTION (3.5 Å)