cDNA-derived amino-acid sequence of a land turtle (Geochelone carbonaria) beta-chain hemoglobin.
The cDNA sequence encoding the turtle Geochelone carbonaria beta-chain was determinated. The isolation of hemoglobin mRNA was based on degenerate primers' PCR in combination with 5'- and 3'-RACE protocol. The full length cDNA is 615 bp with the ATG start codon at position 53 and TGA stop codon at position 495; The AATAAA polyadenylation signal is found at position 599. The deduced polypeptyde contains 146 amino-acid residues. The predicted amino acid sequence shares 83% identity with the beta-globin of a related specie, the aquatic turtle C. p. belli. Otherwise, identity is higher when compared with chicken beta-Hb (80%) than with other reptilian orders (Squamata, 69%, and Crocodilia, 61%). Compared with human HbA, there is 67% identity, and at least three amino acid substitutions could be of some functional significance (Glu43 beta-->Ser, His116 beta-->Thr and His143 beta-->Leu). To our knowledge this represents the first cDNA sequence of a reptile globin gene described.
Bordin
S
S
Centro de Hematologia e Hemoterapia da Unicamp, Universidade Estadual de Campinas, São Paulo, Brazil.
Meza
A N
AN
Saad
S T
ST
Ogo
S H
SH
Costa
F F
FF
D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D005914:Globins / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic; D014426:Turtles / Q000235:genetics*
D018076:DNA, Complementary; D005914:Globins