NMR studies of the fifth transmembrane segment of sarcoplasmic reticulum Ca2+‐ATPase reveals a hinge close to the Ca2+‐ligating residues

FEBS Letters

Nielsen, Gerd¹  Meissner, Axel³  Malmendal, Anders¹  Møller, Jesper V²  Nielsen, Niels Chr¹ 

[1] Interdisciplinary Nanoscience Center (iNANO) and Aarhus University NMR Center, Department of Molecular Biology, University of Aarhus, Langelandsgade 140, DK-8000 Aarhus C, Denmark;Department of Biophysics, University of Aarhus, DK-8000 Aarhus C, Denmark;Department of Chemistry, Carlsberg Laboratory, Gamle Carlsberg Vej 10, DK-2500 Valby, Denmark

关键词: Ca2+-ATPase;    Fifth transmembrane segment M5;    Membrane protein;    Micelle;    Nuclear magnetic resonance;    Sarcoplasmic reticulum;    Sodium dodecyl sulfate;   

DOI  :  10.1016/S0014-5793(03)00448-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Two recent X-ray structures have tremendously increased the understanding of the sarco/endoplasmic reticulum Ca²⁺-ATPase (SERCA) and related proteins. Both structures show the fifth transmembrane span (M5) as a single continuous α-helix. The inherent structural and dynamic features of this span (Lys758–Glu785) were studied in isolation in sodium dodecyl sulfate (SDS) micelles using liquid-state nuclear magnetic resonance (NMR) spectroscopy. We find that a flexible region (Ile765–Asn768) is interrupting the α-helix. The location of the flexible region near the Ca²⁺ binding residues Asn768 and Glu771 suggests that together with a similar region in M6 it has a hinge function that may be important for cooperative Ca²⁺ binding and occlusion.

【 授权许可】

Unknown