Sequence analysis of the junctions between a large inverted repeat and single-copy regions in tobacco chloroplast DNA

Abstract

Tobacco chloroplast DNA contains a large inverted repeat sequence of 26 kilobase pairs (kbp). The inverted repeat is separated by 20 kbp small single-copy and 90 kbp large single-copy regions. We have cloned four DNA fragments containing each junction between the inverted repeat and the single-copy regions. The sequence analysis revealed the exact edges of the inverted repeat. A putative coding region for a ribosomal protein CS19 was found 4 base pairs (bp) away from the inverted repeat on the left margin of the large single-copy region. A sequence AGGAG, which is complementary to the 3′ terminal sequence of tobacco chloroplast 16S rRNA, was found within the inverted repeat. A tRNAHis gene was found 5 bp away from the inverted repeat on the right-hand margin of the large single-copy region.