Structural highlights
Publication Abstract from PubMed
Ca2+/cation antiporters catalyze the exchange of Ca2+ with various cations across biological membranes, to regulate cytosolic calcium levels. The recently reported structure of a prokaryotic Na+/Ca2+ exchanger (NCX_Mj) revealed its overall architecture in an outward-facing state. Here we report the crystal structure of a H+/Ca2+ exchanger from Archaeoglobus fulgidus (CAX_Af) in the two representatives of the inward-facing conformation at 2.3 A resolution. The structures suggested Ca2+ or H+ binds to the cation-binding site mutually exclusively. Structural comparison of CAX_Af with NCX_Mj revealed that the first and sixth transmembrane helices alternately create hydrophilic cavities on the intra- and extracellular sides. The structures and functional analyses provide insight into the mechanism of how the inward- to outward-facing state transition is triggered by the Ca2+ and H+ binding.
Structural Basis for the Counter-Transport Mechanism of a H+/Ca2+ Exchanger.,Nishizawa T, Kita S, Maturana AD, Furuya N, Hirata K, Kasuya G, Ogasawara S, Dohmae N, Iwamoto T, Ishitani R, Nureki O Science. 2013 May 23. PMID:23704374[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Nishizawa T, Kita S, Maturana AD, Furuya N, Hirata K, Kasuya G, Ogasawara S, Dohmae N, Iwamoto T, Ishitani R, Nureki O. Structural Basis for the Counter-Transport Mechanism of a H+/Ca2+ Exchanger. Science. 2013 May 23. PMID:23704374 doi:10.1126/science.1239002
