Structure determination may be a procedure by that the three-dimensional atomic coordinates of a molecule or biomolecule ar resolved victimization Associate in Nursing analytical technique. several techniques ar utilized in structure determination, most ordinarily X-ray physical science, NMR chemical analysis, microscopy and molecular modelling. Structure determination of G macromolecule-coupled receptors (GPCRs) within the inactive state absolute to high-affinity antagonists has been terribly prosperous through the implementation of variety of protein engineering and crystallization methods. However, the structure determination of GPCRs in their totally active state coupled to a G macromolecule remains terribly difficult. Recently, mini-G proteins were developed, that recapitulate the coupling of a full heterotrimeric G macromolecule to a GPCR despite being but third of the scale.