Structural interpretation of the amino acid sequence of a second domain from the Artemia covalent polymer globin.
Artemia has a complex extracellular hemoglobin of Mr 260,000 comprising two globin chains (Mr 130,000) each of which is a polymer of eight covalently linked domains of Mr 16,000. The primary structure of this polymeric globin was studied to understand how globin folded domains are ordered within a globin chain and, in turn, how the latter associate into a functional hemoglobin molecule. Here we report the amino acid sequence of a second domain, E7 (Mr 16,081, excluding the heme), and interpretations of sequence data by computer-assisted alignment and modeling. This clearly shows that, as with domain E1 (Moens, L., Van Hauwaert, M.-L., De Smet, K., Geelen, D., Verpooten, G., Van Beeumen, J., Wodak, S., Alard, P., & Trotman, C. (1988) J. Biol. Chem. 263, 4679-4685), domain E7 is compatible with a globin folded structure of the beta-type chain. Several specific differences of domains E7 and E1 from the classic globins are identified. They possibly can be interpreted in terms of specific requirements for a double octameric functional molecule.
Moens
L
L
Department of Biochemistry, University of Antwerp (UIA), Wilrijk, Belgium.
Van Hauwaert
M L
ML
De Smet
K
K
Ver Donck
K
K
Van De Peer
Y
Y
Van Beeumen
J
J
Wodak
S
S
Alard
P
P
Trotman
C
C
D000595:Amino Acid Sequence; D000818:Animals; D001156:Artemia; D005075:Biological Evolution; D002851:Chromatography, High Pressure Liquid; D005914:Globins / Q000235:genetics*; D006454:Hemoglobins / Q000302:isolation & purification; D006801:Humans; D046911:Macromolecular Substances; D008958:Models, Molecular; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010446:Peptide Fragments / Q000302:isolation & purification; D010449:Peptide Mapping; D011487:Protein Conformation; D012689:Sequence Homology, Nucleic Acid
D006454:Hemoglobins; D046911:Macromolecular Substances; D010446:Peptide Fragments; D005914:Globins