Comparison of the amino acid sequences predicted from the B transcript and theB3  transcript with exon 3 skipped.

A normal B cDNA predicts a polypeptide of 354 amino acids with a transmembrane segment of residues 17 through 37 (double underlined). The amino acid sequence predicted from theB3  transcript with exon 3 skipped lacks 19 amino acid residues in the N-terminal portion and preserves the majority of the transferase protein with the catalytic C-terminal remaining intact. The translation start and stop codons are underlined.