Figure 3.

Structures of RNA polymerase α subunits deduced from rpoA genes of E. coli (33, 34), maize chloroplasts (32), and Chlorella chloroplasts. Functional domains of the E. coli α subunit are indicated at the top. Numbers above the boxes represent numbers of amino acids residues. The α subunits of maize and Chlorella have extra sequences with respect to that of E. coli, and these are shown below with the number of amino acid residues (aa). Corresponding regions (without the extra sequences) between E. coli and maize and between E. coli and Chlorella show 30% and 28% identities, respectively.