Please use this identifier to cite or link to this item:
Title: Structure and dynamics of Ca2+-binding domain 1 of the Na+/Ca2+ exchanger in the presence and in the absence of Ca2+.
Authors: Johnson, E
Bruschweiler-Li, L
Showalter, SA
Vuister, GW
Zhang, F
Brüschweiler, R
First Published: 28-Mar-2008
Citation: J MOL BIOL, 2008, 377 (3), pp. 945-955
Abstract: The Na(+)/Ca(2+) exchanger is the major exporter of Ca(2+) across the cell membrane of cardiomyocytes. The activity of the exchanger is regulated by a large intracellular loop that contains two Ca(2+)-binding domains, calcium-binding domain (CBD) 1 and CBD2. CBD1 binds Ca(2+) with much higher affinity than CBD2 and is considered to be the primary Ca(2+) sensor. The effect of Ca(2+) on the structure and dynamics of CBD1 has been characterized by NMR spectroscopy using chemical shifts, residual dipolar couplings, and spin relaxation. Residual dipolar couplings are used in a new way for residue selection in the determination of the anisotropic rotational diffusion tensor from spin relaxation data. The results provide a highly consistent description across these complementary data sets and show that Ca(2+) binding is accompanied by a selective conformational change among the binding site residues. Residues that exhibit a significant conformational change are also sites of altered dynamics. In particular, Ca(2+) binding restricts the mobility of the major acidic segment and affects the dynamics of several nearby binding loops. These observations indicate that Ca(2+) elicits a local transition to a well-ordered coordination geometry in the CBD1-binding site.
DOI Link: 10.1016/j.jmb.2008.01.046
eISSN: 1089-8638
Type: Journal Article
Appears in Collections:Published Articles, Dept. of Biochemistry

Files in This Item:
There are no files associated with this item.

Items in LRA are protected by copyright, with all rights reserved, unless otherwise indicated.