Analysis of the human apolipoprotein B gene; complete structure of the B-74 region

In this paper we describe the nucleotide sequence of the B-74 region of human apolipoprotein B-100 mRNA. This region comprises the 3'-proximal three-quarters of the mRNA and contains 10,089 nucleotides (nt), 9786 of which are coding. Combining our data with the published sequence of the 5'-proximal one-quarter (i.e., the B-26 region [Protter et al., Proc. Natl. Acad. Sci. USA 83 (1986) 5678-5682] assigns 14,059 nt to the apoB-100 mRNA. The coding sequence spans 13,548 nt or 4516 amino acids (leader peptide excluded). The B-74 part of the apoB gene is built up of five exons separated by small introns, and is dominated by an unusually large exon of 7.5 kb. The derivation of two (EcoRI and XbaI) restriction fragment length polymorphisms occurring in the coding region is discussed.