RNase E Enzymes from Rhodobacter capsulatus and Escherichia coli Differ in Context- and Sequence-Dependent In Vivo Cleavage within the Polycistronic puf mRNA

The 5′ pufQ mRNA segment and the pufLMX mRNA segment of Rhodobacter capsulatus exhibit different stabilities. Degradation of both mRNA segments is initiated by RNase E-mediated endonucleolytic cleavage. While Rhodobacter RNase E does not discriminate between the different sequences present around the cleavage sites within pufQ and pufL, Escherichia coli RNase E shows preference for the sequence harboring more A and U residues.