title: Primary structure of scombrine alpha: two different species with an identical protamine.
abstract: We have studied the protamine scombrine alpha from the mackerel Scomber scombrus. Scombrine alpha is found phosphorylated in spermatid nuclei, but not in nuclei of ripe sperm. It is a typical fish protamine, made up of two distinct molecular species, each of 34 amino acid residues. The primary structure of the main component of scombrine alpha is 100% identical to scombrine gamma, the nonmicroheterogeneous protamine from Scomber australasicus (11). The second component of scombrine alpha is a very minor molecular species that has an isoleucine instead of a valine in position 11. Nuclear sperm-specific basic proteins display an enormous interspecific variability and it is very surprising that two different species show identical protamines. In this work we suggest that evolutionary changes in primary structure of protamines are restricted by several constitutive factors, especially when protamines either lack or have a low degree of microheterogeneity.
authors.affiliation: Flanders Interuniversity Institute of Biotechnology (UIB), Department of Biochemistry, Faculty of Medicine, University of Gent, Belgium.
authors.forename: C
authors.initials: C
authors.lastname: Buesa
authors.forename: L
authors.initials: L
authors.lastname: del Valle
authors.forename: N
authors.initials: N
authors.lastname: Saperas
authors.forename: M
authors.initials: M
authors.lastname: Goethals
authors.forename: D
authors.initials: D
authors.lastname: Lloris
authors.forename: M
authors.initials: M
authors.lastname: Chiva
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D019143:Evolution, Molecular; D005399:Fishes / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011479:Protamines / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D013087:Spermatids / Q000737:chemistry; D013094:Spermatozoa / Q000737:chemistry
chemical_list: D000596:Amino Acids; D011479:Protamines; C083061:scombrine