Lariat structure at the branch point (see also Figure 28.32 on page 1098). The 5'-phosphate of the G at the 5'-end of the intron is linked to the 2'-hydroxyl of the A at the branch point to form a 5'-to-2' phosphodiester linkage, which is located about 30 nucleotides from the 3' end of the intron sequence. The branched chain remains in the final excised intron sequence and is responsible for its lariat form. The dashed line represents intron sequences.