G-protein–coupled receptors (GPCRs) are signalling proteins which enable cells to communicate with each other and the surrounding environment. They provide the molecular framework and mechanism for the transmission of a wide variety of signals over the cell membrane, between cells and over long distances in the body. GPCRs represent the largest family of membrane proteins in the human genome. They are remarkably versatile and are responsible for the majority of transmembrane signal transduction in response to hormones and neurotransmitters. GPCRs activate G proteins, which subsequently regulate downstream effector proteins.
The groundbreaking studies by Lefkowitz and Kobilka reveal the inner workings of this vitally important family of receptors. The crystal structures of the beta2 adrenergic receptor were determined using X-ray diffraction by Kobilka's group. The structures 2rh1, 2r4r and 2r4s were published and released in the Protein Data Bank in 2007. Subsequently, the structure of a G protein (Gs) bound to the beta2 adrenergic receptor 3sn6 was determined using X-ray diffraction by the same group at a resolution of 3.2 Å and published in 2011, providing important insights into how GPCRs activate G proteins.
With approximately 40–50% of currently marketed drugs targeting GPCRs this family of receptors are particularly important for drug discovery and this is reflected in the number of GPCR structures that have been published over the past few years.
Timeline of structural biology related Nobel Prizes (Drag or double-click timeline to navigate.)
X-ray crystallography is a method for determining the three-dimensional structure of molecules organised within a crystal. The crystal is exposed to a beam of X-rays and the molecules within the crystal diffract the X-rays in specific directions. By studying the diffraction pattern and the intensities and position of the diffracted beam, crystallographers can identify the position and atomic details of the molecules.
This year’s Nobel Prize is yet another example of the extraordinary contribution made by crystallographers and structural biologists to the fields of chemistry, biology and medicine. The Foundation has awarded more than 20 Nobel Prizes to structural biologists in the past 50 years. These include the Nobel Prize for Chemistry in 1962 (for studies of the structures of globular proteins) to John Kendrew and Max Perutz and the Nobel Prize in Physiology or Medicine in the same year to Francis Crick, James Watson and Maurice Wilkins (for their studies of "The helical structure of DNA").
Information generated by the structural biology community, be it the atomic details of ribosomes, haemoglobin or any other protein or nucleic-acid molecules or complexes, is archived in the Protein Data Bank (PDB). The accumulated data in the PDB archive provides a wealth of knowledge on protein structure and function. The PDB archive was established in 1972 and is now managed by the four Worldwide Protein Data Bank (wwPDB) partners - RCSB and BMRB in the USA, PDBj in Japan and the Protein Data Bank in Europe (PDBe) at the European Bioinformatics Institute (EBI) in Cambridge, UK. The four partners ensure that the data is available to the wider scientific community for research and development in the field of biology and medicine.
This page was created by the following members of the PDBe team: Sameer Velankar, Gary Battle, Glen van Ginkel, Matthew Conroy, John Berrisford, Gerard Kleywegt. For more information about PDBe or the GPCR structures deposited in the PDB, please contact Gary Battle.