Structure of the human hemopexin gene and evidence for intron-mediated evolution.
The human hemopexin gene was isolated and its structure determined. The gene spans approximately 12 kb and is interrupted by nine introns. When the intron/exon pattern was examined with respect to the polypeptide segments they encode, a direct correspondence between exons and the 10 repeating units in the protein was observed. The introns are not randomly placed; they fall in the middle of the region of amino acid sequence homology in strikingly similar locations in 6 of the 10 units and in a symmetrical position in the two halves of the coding sequence. These features strongly support the hypothesis that the gene evolved through intron-mediated duplications of a primordial sequence to a five-exon cluster. A more recent gene duplication led to the present-day gene organization.
Altruda
F
F
Cattedra di Biologia Generale, Torino, Italy.
Poli
V
V
Restagno
G
G
Silengo
L
L
D000595:Amino Acid Sequence; D001483:Base Sequence; D005075:Biological Evolution; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D004262:DNA Restriction Enzymes; D004926:Escherichia coli / Q000235:genetics; D005796:Genes; D006466:Hemopexin / Q000235:genetics*; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data
D004247:DNA; D006466:Hemopexin; D004262:DNA Restriction Enzymes