Chemosensory Receptors in Vertebrates: Structure and Computational Modeling Insights

Chemical communication is based on the release of chemical cues, including odorants, tastants and semiochemicals, which can be perceived by animals and trigger physiological and behavioral responses. These compounds exhibit a wide size and properties range, spanning from small volatile molecules to soluble proteins, and are perceived by various chemosensory receptors (CRs). The structure of these receptors is very well conserved across all organisms and within the family to which they belong, the G-protein-coupled receptor (GPCR) family. It is characterized by highly conserved seven-transmembrane (7TM) α-helices. However, the characteristics of these proteins and the methods used to study their structures are limiting factors for resolving their structures. Due to the importance of CRs-especially olfactory and taste receptors, responsible for two of our five basic senses-alternative methods are utilized to overcome these structural challenges. Indeed, in silico structural biology is an expanding field that is very useful for CR structural studies. Since the 1960s, many algorithms have been developed and improved in an attempt to resolve protein structure. We review the current knowledge regarding different vertebrate CRs in this study, with an emphasis on the in silico structural methods employed to improve our understanding of CR structures.