5K8Q

Crystal Structure of Calcium-loaded Calmodulin in complex with STRA6 CaMBP2-site peptide.

Summary for 5K8Q

• Entry DOI: 10.2210/pdb5k8q/pdb
• Descriptor: Calmodulin, Zgc:136689, CALCIUM ION, ... (5 entities in total)
• Functional Keywords: calmodulin, stra6, peptide complex, unique fold, metal binding protein
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 2
• Total formula weight: 20162.49

Authors

Stowe, S.D.,Clarke, O.B.,Cavalier, M.C.,Godoy-Ruiz, R.,Mancia, F.,Weber, D.J. (deposition date: 2016-05-30, release date: 2016-08-24, Last modification date: 2024-04-03)

Primary citation

Chen, Y.,Clarke, O.B.,Kim, J.,Stowe, S.,Kim, Y.K.,Assur, Z.,Cavalier, M.,Godoy-Ruiz, R.,von Alpen, D.C.,Manzini, C.,Blaner, W.S.,Frank, J.,Quadro, L.,Weber, D.J.,Shapiro, L.,Hendrickson, W.A.,Mancia, F.
Structure of the STRA6 receptor for retinol uptake.
Science, 353:-, 2016

PubMed Abstract: Vitamin A homeostasis is critical to normal cellular function. Retinol-binding protein (RBP) is the sole specific carrier in the bloodstream for hydrophobic retinol, the main form in which vitamin A is transported. The integral membrane receptor STRA6 mediates cellular uptake of vitamin A by recognizing RBP-retinol to trigger release and internalization of retinol. We present the structure of zebrafish STRA6 determined to 3.9-angstrom resolution by single-particle cryo-electron microscopy. STRA6 has one intramembrane and nine transmembrane helices in an intricate dimeric assembly. Unexpectedly, calmodulin is bound tightly to STRA6 in a noncanonical arrangement. Residues involved with RBP binding map to an archlike structure that covers a deep lipophilic cleft. This cleft is open to the membrane, suggesting a possible mode for internalization of retinol through direct diffusion into the lipid bilayer.

PubMed: 27563101
DOI: 10.1126/science.aad8266

Experimental method

X-RAY DIFFRACTION (1.739 Å)