A mitochondrial intron sequence in the 5'-flanking region of a plant nuclear lectin gene.

A sequence fragment from the cis-splicing intron between exons a and b of the NADH-dehydrogenase subunit 5 gene (nad5) in plant mitochondria is also present in one of two closely related nuclear-encoded lectin genes of Dolichos biflorus. This sequence of 116 nucleotides is the major difference in the 5'-flanking region of two recently described lectin genes (Harada et al. 1990). The stem and leaf lectin DB58 does not contain the insert, while the otherwise more than 90% identical 5'-flanking region of the seed lectin is interrupted by this mitochondrial intron sequence.