Characterization of a novel theta-type plasmid pSM409 of Enterococcus faecium RME isolated from raw milk

•A novel circular plasmid pSM409 (4303 bp) with 33.6% GC content from E. faecium RME, a raw-milk isolate.•The plasmid is mosaic in nature.•Iteron-based origin of replication suggests that pSM409 replicates via the Theta mechanism.•The replicon is unique to the plasmid pSM409.•DNA binding domain of RepB and the associated iteron of theta type plasmids bears a clade specific relationship.