6LN5

CryoEM structure of SERCA2b T1032stop in E1-2Ca2+-AMPPCP (class1)

Summary for 6LN5

• Entry DOI: 10.2210/pdb6ln5/pdb
• EMDB information: 0924
• Descriptor: Sarcoplasmic/endoplasmic reticulum calcium ATPase 2, PHOSPHOMETHYLPHOSPHONIC ACID ADENYLATE ESTER, MAGNESIUM ION, ... (4 entities in total)
• Functional Keywords: calcium, metal transport
• Biological source: Homo sapiens (Human)
• Total number of polymer chains: 1
• Total formula weight: 117042.12

Authors

Zhang, Y.,Tsutsumi, A.,Watanabe, S.,Inaba, K. (deposition date: 2019-12-28, release date: 2020-08-26, Last modification date: 2024-11-06)

Primary citation

Zhang, Y.,Inoue, M.,Tsutsumi, A.,Watanabe, S.,Nishizawa, T.,Nagata, K.,Kikkawa, M.,Inaba, K.
Cryo-EM structures of SERCA2b reveal the mechanism of regulation by the luminal extension tail.
Sci Adv, 6:eabb0147-eabb0147, 2020

PubMed Abstract: Sarco/endoplasmic reticulum Ca ATPase (SERCA) pumps Ca from the cytosol into the ER and maintains the cellular calcium homeostasis. Herein, we present cryo-electron microscopy (cryo-EM) structures of human SERCA2b in E1∙2Ca-adenylyl methylenediphosphonate (AMPPCP) and E2-BeF states at 2.9- and 2.8-Å resolutions, respectively. The structures revealed that the luminal extension tail (LE) characteristic of SERCA2b runs parallel to the lipid-water boundary near the luminal ends of transmembrane (TM) helices TM10 and TM7 and approaches the luminal loop flanked by TM7 and TM8. While the LE served to stabilize the cytosolic and TM domain arrangement of SERCA2b, deletion of the LE rendered the overall conformation resemble that of SERCA1a and SERCA2a and allowed multiple conformations. Thus, the LE appears to play a critical role in conformational regulation in SERCA2b, which likely explains the different kinetic properties of SERCA2b from those of other isoforms lacking the LE.

PubMed: 32851169
DOI: 10.1126/sciadv.abb0147

Experimental method

ELECTRON MICROSCOPY (2.8 Å)