Possible regulation of DNA methyltransferase expression by RNA processing in streptococcus pneumoniae

Atypical ribosome-binding sites lacking Shine-Dalgarno sequences appear to be used for translation of the DpnM and DpnA DNA methyltransferases of the DpnII restriction system. Preliminary results indicate that the 5′-endpoints of DpnII system mRNAs result from degradation of the original transcript. These tentative findings serve as the basis for a possible regulatory model that would accommodate the DpnII cassette either as a single copy in the chromosome or on a multicopy plasmid.