3A3K

Reversibly bound chloride in the atrial natriuretic peptide receptor hormone-binding domain

Summary for 3A3K

• Entry DOI: 10.2210/pdb3a3k/pdb
• Related: 1DP4 1T34
• Descriptor: Atrial natriuretic peptide receptor A, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, 2-acetamido-2-deoxy-beta-D-glucopyranose, ... (6 entities in total)
• Functional Keywords: natriuretic peptide receptor, guanylyl-cyclase-coupled receptor, chloride binding motif, signal transduction, signaling protein, membrane protein, cgmp biosynthesis, chloride, disulfide bond, glycoprotein, gtp-binding, lyase, membrane, nucleotide-binding, phosphoprotein, receptor, transmembrane
• Biological source: Rattus norvegicus (Rat)
• Cellular location: Membrane; Single-pass type I membrane protein: P18910
• Total number of polymer chains: 2
• Total formula weight: 100052.07

Authors

Ogawa, H.,Qiu, Y.,Ogata, C.M.,Misono, K.S. (deposition date: 2009-06-14, release date: 2010-03-16, Last modification date: 2024-10-30)

Primary citation

Ogawa, H.,Qiu, Y.,Philo, J.S.,Arakawa, T.,Ogata, C.M.,Misono, K.S.
Reversibly bound chloride in the atrial natriuretic peptide receptor hormone-binding domain: Possible allosteric regulation and a conserved structural motif for the chloride-binding site.
Protein Sci., 19:544-557, 2010

PubMed Abstract: The binding of atrial natriuretic peptide (ANP) to its receptor requires chloride, and it is chloride concentration dependent. The extracellular domain (ECD) of the ANP receptor (ANPR) contains a chloride near the ANP-binding site, suggesting a possible regulatory role. The bound chloride, however, is completely buried in the polypeptide fold, and its functional role has remained unclear. Here, we have confirmed that chloride is necessary for ANP binding to the recombinant ECD or the full-length ANPR expressed in CHO cells. ECD without chloride (ECD(-)) did not bind ANP. Its binding activity was fully restored by bromide or chloride addition. A new X-ray structure of the bromide-bound ECD is essentially identical to that of the chloride-bound ECD. Furthermore, bromide atoms are localized at the same positions as chloride atoms both in the apo and in the ANP-bound structures, indicating exchangeable and reversible halide binding. Far-UV CD and thermal unfolding data show that ECD(-) largely retains the native structure. Sedimentation equilibrium in the absence of chloride shows that ECD(-) forms a strongly associated dimer, possibly preventing the structural rearrangement of the two monomers that is necessary for ANP binding. The primary and tertiary structures of the chloride-binding site in ANPR are highly conserved among receptor-guanylate cyclases and metabotropic glutamate receptors. The chloride-dependent ANP binding, reversible chloride binding, and the highly conserved chloride-binding site motif suggest a regulatory role for the receptor bound chloride. Chloride-dependent regulation of ANPR may operate in the kidney, modulating ANP-induced natriuresis.

PubMed: 20066666
DOI: 10.1002/pro.332

Experimental method

X-RAY DIFFRACTION (2.5 Å)