title: Identification and characterization of a TAP-family gene in the lamprey.
abstract: An expressed sequence tag obtained from a sea lamprey ( Petromyzon marinus) cDNA library was used to obtain a full-length coding sequence showing significant similarity to ABCB transporter proteins. The sequence is closely related to the mammalian ABCB9 protein and the TAP1 and TAP2 proteins that transport peptides for loading onto nascent Mhc class I molecules. The Pema-ABCB9 gene has an exon-intron organization similar to that of the mammalian TAP genes, with the exception of exon 2, which in the lamprey is split into two by a 949-bp long intron. The gene probably occurs in a single copy in the haploid lamprey genome. The ABCB9 genes appear to be evolving four-to-ten times slower than the TAP1 and TAP2 genes. Six putative transmembrane helices and the nucleotide-binding domain of the lamprey ABCB9 protein show high sequence similarity with the TAP1 and TAP2 molecules. The lamprey protein also contains sequence stretches that resemble the putative peptide interacting parts of the TAP1 and TAP2 molecules, but are peppered with ABCB9-specific residues.
authors.affiliation: Abteilung Immungenetik, Max-Planck-Institut für Biologie, Corrensstrasse 42, 72076, Tübingen, Germany. tanya@tuebingen.mpg.de
authors.forename: Tatiana S
authors.initials: TS
authors.lastname: Uinuk-ool
authors.forename: Werner E
authors.initials: WE
authors.lastname: Mayer
authors.forename: Akie
authors.initials: A
authors.lastname: Sato
authors.forename: Naoko
authors.initials: N
authors.lastname: Takezaki
authors.forename: Lesley
authors.initials: L
authors.lastname: Benyon
authors.forename: Max D
authors.initials: MD
authors.lastname: Cooper
authors.forename: Jan
authors.initials: J
authors.lastname: Klein
mesh_terms: D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001692:Biological Transport; D015139:Blotting, Southern; D003001:Cloning, Molecular; D017931:DNA Primers / Q000737:chemistry; D005091:Exons; D015723:Gene Library; D006801:Humans; D007438:Introns; D007798:Lampreys / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012313:RNA / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid
chemical_list: C412573:ABCB9 protein, human; D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters; D017931:DNA Primers; C073119:TAP1 protein, human; C071692:TAP2 protein, human; D012313:RNA