RRC ID 27307
Author Nishizawa T, Kita S, Maturana AD, Furuya N, Hirata K, Kasuya G, Ogasawara S, Dohmae N, Iwamoto T, Ishitani R, Nureki O.
Title Structural basis for the counter-transport mechanism of a H+/Ca2+ exchanger.
Journal Science
Abstract Ca(2+)/cation antiporters catalyze the exchange of Ca(2+) with various cations across biological membranes to regulate cytosolic calcium levels. The recently reported structure of a prokaryotic Na(+)/Ca(2+) exchanger (NCX_Mj) revealed its overall architecture in an outward-facing state. Here, we report the crystal structure of a H(+)/Ca(2+) exchanger from Archaeoglobus fulgidus (CAX_Af) in the two representatives of the inward-facing conformation at 2.3 Å resolution. The structures suggested Ca(2+) 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 Ca(2+) and H(+) binding.
Volume 341(6142)
Pages 168-72
Published 2013-7-12
DOI 10.1126/science.1239002
PII science.1239002
PMID 23704374
MeSH Antiporters / chemistry* Antiporters / genetics Antiporters / metabolism Archaeal Proteins / chemistry* Archaeal Proteins / genetics Archaeal Proteins / metabolism Archaeoglobus fulgidus / metabolism* Binding Sites Calcium / chemistry Calcium / metabolism Cation Transport Proteins / chemistry* Cation Transport Proteins / genetics Cation Transport Proteins / metabolism Crystallography, X-Ray Hydrogen / chemistry Hydrogen / metabolism Protein Structure, Secondary Protein Structure, Tertiary
IF 41.058
Times Cited 27
DNA material Genomic DNA of Archaeoglobus fulgidus JCM 9628T (JGD06275)
General Microbes JCM 9628