title: Molecular characterization of hemoglobin alpha-D chains from Geochelone carbonaria and Geochelone denticulata land turtles.
abstract: In order to help elucidate the evolution of alpha-globins, the complete cDNA and amino acid sequences of Geochelone carbonaria and Geochelone denticulata land turtles alpha-D chains have been described. In G. carbonaria, the cDNA is 539 bp with ATG start codon located at position 46, TGA stop codon at position 469 and AATAAA polyadenylation signal at position 520. In G. denticulata, the cDNA is 536 bp with ATG start codon located at position 46, TGA stop codon at position 469 and AATAAA polyadenylation signal at position 517. Both cDNAs codify 141 amino acid residues, differing from each other in only four amino acid residues. When comparing with human Hb alpha-chain, alterations in important regions can be noted: alpha110 Ala-Gly, alpha114 Pro-Gly, alpha117 Phe-Tyr and alpha122 His-Gln. There is a high homology between the amino acids of these turtles when compared with chicken alpha-D chains, progressively decreasing when compared with human, crocodile, snake, frog and fish alpha-chains. Phylogenetic analysis of alpha-D chains shows that those of turtles are closer to those of birds than to snakes and lizards.
authors.affiliation: Department of Clinical Medicine--Hemocentro, School of Medical Sciences, State University of Campinas, Cidade Universitária Zeferino Vaz S/N, Caixa Postal 6198 Campinas, SP, CEP 13083-970, Brazil. melomb@uol.com.br
authors.forename: Mônica B
authors.initials: MB
authors.lastname: Melo
authors.forename: Silvana
authors.initials: S
authors.lastname: Bordin
authors.forename: Adriana S S
authors.initials: AS
authors.lastname: Duarte
authors.forename: Satie H
authors.initials: SH
authors.lastname: Ogo
authors.forename: Márcio A
authors.initials: MA
authors.lastname: Torsoni
authors.forename: Sara T O
authors.initials: ST
authors.lastname: Saad
authors.forename: Fernando F
authors.initials: FF
authors.lastname: Costa
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018076:DNA, Complementary / Q000235:genetics; D006455:Hemoglobins, Abnormal / Q000737:chemistry* / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D014426:Turtles / Q000235:genetics*
chemical_list: D018076:DNA, Complementary; D006455:Hemoglobins, Abnormal; C032001:hemoglobin D