Publication Abstract from PubMed
The Na+/Ca2+ exchanger is a plasma membrane protein that regulates intracellular Ca2+ levels in cardiac myocytes. Transport activity is governed by Ca2+, and the primary Ca2+ sensor (CBD1) is located in a large cytoplasmic loop connecting two transmembrane helices. The binding of Ca2+ to the CBD1 sensory domain results in conformational changes that stimulate the exchanger to extrude Ca2+. Here, we present a crystal structure of CBD1 at 2.5A resolution, which reveals a novel Ca2+ binding site consisting of four Ca2+ ions arranged in a tight planar cluster. This intricate coordination pattern for a Ca2+ binding cluster is indicative of a highly sensitive Ca2+ sensor and may represent a general platform for Ca2+ sensing.
The crystal structure of the primary Ca2+ sensor of the Na+/Ca2+ exchanger reveals a novel Ca2+ binding motif.,Nicoll DA, Sawaya MR, Kwon S, Cascio D, Philipson KD, Abramson J J Biol Chem. 2006 Aug 4;281(31):21577-81. Epub 2006 Jun 14. PMID:16774926[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
