title: Characteristic amino acid combinations in olfactory G protein-coupled receptors.
abstract: The human olfactory subgenome has recently been fully characterized with over 1000 genes. Although as many as two thirds of them are expected to be pseudogenes, it still leaves us with about half of all human G protein-coupled receptors being olfactory. It is therefore of great interest to characterize olfactory receptors with high precision. Usually it is done through sequence motifs that are not fully conserved, making an exact characterization difficult. In this paper, we propose a rule-based characterization of olfactory receptors derived from a multiple sequence alignment of human GPCRs. We show that just seven alignment sites are sufficient to characterize 99% of human olfactory GPCRs with one feature, a tyrosine at site 7.41, being of particular importance. We also show dependencies between sites near the extracellular and intracellular region of a membrane-embedded receptor, indicating that olfactory receptors are characterized by a combination of important residues in these two areas, whereas nonolfactory receptors tend to have residues of lower importance at the same sites.
authors.affiliation: Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, Leiden, The Netherlands. elena.samsonova@liacs.nl
authors.forename: Elena V
authors.initials: EV
authors.lastname: Samsonova
authors.forename: Peter
authors.initials: P
authors.lastname: Krause
authors.forename: Thomas
authors.initials: T
authors.lastname: Bäck
authors.forename: Ad P
authors.initials: AP
authors.lastname: IJzerman
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry*; D019295:Computational Biology; D017143:Fuzzy Logic; D006801:Humans; D008954:Models, Biological; D008958:Models, Molecular; D011487:Protein Conformation; D018035:Receptors, Odorant / Q000737:chemistry*; D016415:Sequence Alignment
chemical_list: D000596:Amino Acids; D018035:Receptors, Odorant