title: Primate ABO glycosyltransferases: evidence for trans-species evolution.
abstract: The human ABO blood group system is controlled by alleles at a single locus on chromosome 9. The alleles encode glycosyltransferases, which add different sugar residues to the terminal part of the oligosaccharide core, thus generating the A or B antigens; an allele encoding enzymatically inactive protein is responsible for the blood group O. The A and B antigens are present not only in humans, but also in many other primate species and it has been proposed that the AB polymorphism was established long before these species diverged. Here we provide molecular evidence for the trans-species evolution of the AB polymorphism. Polymerase-chain reaction (PCR) amplification and sequencing has revealed that the critical substitutions differentiating the A and B genes occurred before the divergence of the lineages leading to humans, chimpanzees, gorillas, and orangutans. This polymorphism is therefore at least 13 million years old and is most likely maintained by selection. Comparison of the sequences derived from different species indicates that the difference in enzymatic activities between the A and B transferases is caused by two single nucleotide substitutions responsible for Leu-Met and Gly-Ala replacement at positions 265 and 267 in the polypeptide chains, respectively.
authors.affiliation: Department of Microbiology, Southern Illinois University, Carbondale 62901-6508.
authors.forename: J M
authors.initials: JM
authors.lastname: Martinko
authors.forename: V
authors.initials: V
authors.lastname: Vincek
authors.forename: D
authors.initials: D
authors.lastname: Klein
authors.forename: J
authors.initials: J
authors.lastname: Klein
mesh_terms: D000017:ABO Blood-Group System / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D003001:Cloning, Molecular; D004247:DNA; D016695:Glycosyltransferases / Q000235:genetics*; D006071:Gorilla gorilla; D008969:Molecular Sequence Data; D002679:Pan troglodytes; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011148:Pongo pygmaeus; D011323:Primates / Q000145:classification / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
chemical_list: D000017:ABO Blood-Group System; D004247:DNA; D016695:Glycosyltransferases