Structure of the murine gene encoding apolipoprotein A-I

A 1.6-kb DNA fragment containing the gene encoding apolipoprotein A-I from the mouse, Mus musculus, has been cloned and sequenced. It contains three exons separated by two introns and encodes a secreted polypeptide of 262 amino acids (aa), 238 of which constitute the mature protein. Comparisons with the rat and human proteins indicate moderate levels of shared identity (71 and 66%, respectively), although the overall aa compositions yield proteins with identical pIs (5.4). Kyte-Doolittle analyses of the three proteins indicate that there is no significant difference in the structure of these apolipoproteins.