Structure of human ferritin light subunit messenger RNA: comparison with heavy subunit message and functional implications.

摘要: Abstract Ferritin has a protein shell of 5 X 10(6) Da consisting 24 subunits two types, heavier (H) chain 21,000 and lighter (L) 19,000 Da. A cDNA clone the messenger for L subunit been isolated from human monocyte-like leukemia cell line. The contains an open reading frame 522 nucleotides coding amino acid sequence matching 97% published liver ferritin determined by sequenator, but it corresponds to only 55% reported H-subunit clone. Nevertheless, computer analysis conformations predicted frames H clones shows that most differences are conservative would allow both form five alpha-helices beta-turns established x-ray crystallography horse spleen subunits. This suggests structurally interchangeable in forming apoferritin shell. 5' untranslated region our considerable homology with rat immediately upstream initiator codon, notably showing identical 10 at same position may participate regulating known activation mRNA after iron administration. Extensive homology, including several blocks nucleotides, was identified between 3' regions clones. common structural features lead us conclude they have diverged single ancestral gene.