Genetic organization of plasmids pMTH1 and pMTH4 of P. methylutens DM12. (A) Plasmid pMTH1. The region responsible for the stable maintenance of the plasmid, coding for replication (REP) and stabilization (STA) systems, is shown in yellow. The proximal part of the truncated ISPme2-like element is marked. ISPme1 is marked in red with thick yellow lines at both ends, corresponding to the IRR and IRL. The predicted TMos are indicated. The 3′-end regions of the A-type TMos are shown in blue, and those of the type B module are shown in green. The sites corresponding to the 3′ endpoints of TMo(ISPme1)A6 and TMo(ISPme1)A8 are marked by arrows within TMo(ISPme1)A7 (carries the longest 3′-end region of TMos of type A). The putative function of the predicted ORFs is based on a protein domain search (see the supplemental material for details). (B) Plasmid pMTH4, a deletion derivative of pMTH1. The hybrid TMos of pMTH4 are indicated. TMo(ISPme1)A6/7 resulted from homologous recombination between TMo(ISPme1)A6 and TMo(ISPme1)A7, and TMo(ISPme1)B8 was captured by entrapment vector pEBB10. CoA, coenzyme A.