Sequence analysis and tissue expression of a non-Bohr beta-globin cDNA from Atlantic salmon.
The presence of a haemoglobin protein which does not exhibit a Bohr effect has been found only in fish living in fast flowing waters. We report the cloning of the first non-Bohr effect beta-globin cDNA from an adult Atlantic salmon kidney bank. Nucleotide sequence analysis of this cDNA shows that the predicted beta-globin peptide comprises 147 amino acids with a calculated molecular mass of 15 975 Da and an overall amino acid homology of 40 to 50% to higher vertebrates and 60-90% to fish sequences. This sequence confirms the important amino acid residues which are changed thus causing loss of the Bohr effect [Powers, D.A. and Edmunson, A.B. (1972) Multiple hemoglobins of catostomid fish. J. Biol. Chem. 247, 6686-6693; Brunori, M. (1975) Molecular adaptation to physiological requirements: the hemoglobin system of trout. Curr. Topics Cell. Regul. 9, 1-39]. This loss allows the haemoglobin protein to have a higher oxygen affinity, as it does not release oxygen when the pH of the surrounding environment decreases, which is an important ability for the fish in times of stress.
McMorrow
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T
Microbiology Department, University College, Galway, Ireland. mcmorrow@ch1.fgg.eur.nl
Wagner
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A
Harte
T
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Gannon
F
F
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D005796:Genes; D005914:Globins / Q000096:biosynthesis* / Q000235:genetics* / Q000302:isolation & purification; D007668:Kidney / Q000378:metabolism; D008969:Molecular Sequence Data; D009928:Organ Specificity / Q000235:genetics; D010108:Oxyhemoglobins / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012474:Salmon / Q000097:blood* / Q000235:genetics*; D017422:Sequence Analysis, DNA / Q000379:methods
D017931:DNA Primers; D018076:DNA, Complementary; D010108:Oxyhemoglobins; D005914:Globins