Open AccessA C‐terminal segment of the V 1 R vasopressin receptor is unstructured in the crystal structure of its chimera with the maltose‐binding protein
Author(s) -
Mahmood Syed Saad,
Stanley Nithianantham,
Xu Zhen,
Wu Nan,
Thibonnier Marc,
Adikesavan Nallini Vijayarangan,
Shoham Menachem
Publication year - 2005
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309105007293
Subject(s) - g protein coupled receptor , transmembrane protein , receptor , maltose binding protein , cytoplasm , chimera (genetics) , biology , microbiology and biotechnology , chemistry , biophysics , biochemistry , fusion protein , recombinant dna , gene
The V 1 vascular vasopressin receptor (V 1 R) is a G‐protein‐coupled receptor (GPCR) involved in the regulation of body‐fluid osmolality, blood volume and blood pressure. Signal transduction is mediated by the third intracellular loop of this seven‐transmembrane protein as well as by the C‐terminal cytoplasmic segment. A chimera of the maltose‐binding protein (MBP) and the C‐terminal segment of V 1 R has been cloned, expressed, purified and crystallized. The crystals belong to space group P 2 1 , with unit‐cell parameters a = 51.10, b = 66.56, c = 115.72 Å, β = 95.99°. The 1.8 Å crystal structure reveals the conformation of MBP and part of the linker region of this chimera, with the C‐terminal segment being unstructured. This may reflect a conformational plasticity in the C‐terminal segment that may be necessary for proper function of V 1 R.