We found a matchYour institution may have access to this item. Find your institution then sign in to continue.TitleClassification of G-protein coupled receptors at four levels.AuthorsGao QB; Wang ZZPublicationProtein engineering, design & selection : PEDS, 2006, Vol 19, Issue 11, p511ISSN1741-0126Publication typearticleDOI10.1093/protein/gzl038