A tobacco chloroplast DNA sequence possibly coding for a polypeptide similar to <i>E. coli</i> RNA polymerase β‐subunit

Abstract

DNA sequencing has revealed a long open reading frame (ORF) in the large single-copy region of tobacco chloroplast DNA. This ORF consists of 1070 codons and its deduced amino acid sequence shows about 39% homology to that of the beta-subunit of E. coli RNA polymerase. This finding raises a possibility that some of the chloroplast RNA polymerase subunits are coded for by the chloroplast genome.