title: Early vertebrate evolution of the TATA-binding protein, TBP.
abstract: TBP functions in transcription initiation in all eukaryotes and in Archaebacteria. Although the 181-amino acid (aa) carboxyl (C-) terminal core of the protein is highly conserved, TBP proteins from different phyla exhibit diverse sequences in their amino (N-) terminal region. In mice, the TBP N-terminus plays a role in protecting the placenta from maternal rejection; however the presence of similar TBP N-termini in nontherian tetrapods suggests that this domain also has more primitive functions. To gain insights into the pretherian functions of the N-terminus, we investigated its phylogenetic distribution. TBP cDNAs were isolated from representative nontetrapod jawed vertebrates (zebrafish and shark), from more primitive jawless vertebrates (lamprey and hagfish), and from a prevertebrate cephalochordate (amphioxus). Results showed that the tetrapod N-terminus likely arose coincident with the earliest vertebrates. The primary structures of vertebrate N-termini indicates that, historically, this domain has undergone events involving intragenic duplication and modification of short oligopeptide-encoding DNA sequences, which might have provided a mechanism of de novo evolution of this polypeptide.
authors.affiliation: Veterinary Molecular Biology, Marsh Labs, Montana State University, USA.
authors.forename: Alla A
authors.initials: AA
authors.lastname: Bondareva
authors.forename: Edward E
authors.initials: EE
authors.lastname: Schmidt
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018076:DNA, Complementary / Q000378:metabolism; D019143:Evolution, Molecular; D005091:Exons; D005399:Fishes; D015723:Gene Library; D007438:Introns; D051379:Mice; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D013045:Species Specificity; D035181:TATA-Box Binding Protein / Q000235:genetics*
chemical_list: D018076:DNA, Complementary; D010455:Peptides; D035181:TATA-Box Binding Protein