Figure 4

Diagrammatic representation of the arrangements of two largest subunits of RNA polymerase, i.e. β subunit (RpoB) and β' subunit (RpoC) in different bacteria. In contrast to other bacteria where these proteins are made as distinct polypeptides, in Helicobacter and Wolinella a rare genetic event has led to fusion/joining of the genes for these proteins so that they are now made as a single large polypeptide.