title: The multigenic family of the extracellular hemoglobin from the annelid polychaete Arenicola marina.
abstract: The extracellular hemoglobin of the lugworm Arenicola marina which inhabits on the intertidal area, a sulfide-rich environment, comprises eight globin chains previously determined by mass spectrometry. We have cloned and sequenced five of the globin components. The deduced amino-acid sequences exhibit an extracellular signal peptide and two cysteine residues involved in an internal disulfide bond. The molecular weights calculated from the globin primary structures obtained from complete cDNA sequences are in good agreement with the mass spectrometry values obtained with the native hemoglobin. Phylogenetic analysis has allowed assigning the five A. marina sequences to the different globin sub-families. Two of the globins were found to be A2 globin chains lacking the cysteine residues proposed to be involved in the binding of hydrogen sulfide by such hemoglobin. We discuss the unusual absence of these cysteines in the light of their invariant occurrence in the A2 subfamily of hemoglobins from annelids inhabiting sulfide-rich environments.
authors.affiliation: Equipe Ecophysiologie: Adaptation et Evolution Moléculaires, UPMC, CNRS UMR 7144, Station Biologique, BP 74, 29682 Roscoff cedex, France. chabasse@sb-roscoff.fr
authors.forename: Christine
authors.initials: C
authors.lastname: Chabasse
authors.forename: Xavier
authors.initials: X
authors.lastname: Bailly
authors.forename: Morgane
authors.initials: M
authors.lastname: Rousselot
authors.forename: Franck
authors.initials: F
authors.lastname: Zal
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003545:Cysteine / Q000032:analysis; D004220:Disulfides / Q000378:metabolism; D004777:Environment; D005110:Extracellular Space; D005914:Globins / Q000737:chemistry; D006454:Hemoglobins / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D011077:Polychaeta / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D013440:Sulfides / Q000378:metabolism
chemical_list: D004220:Disulfides; D006454:Hemoglobins; D013440:Sulfides; D005914:Globins; D003545:Cysteine