Regulatory circuits for plasmid survival

Bacterial plasmids deploy a diverse range of regulatory mechanisms to contr ol expression of the functions they need to survive in the host population. Understanding of the mechanisms by which autoregulatory circuits control p lasmid survival functions, in particular plasmid replication, has been adva nced by recent studies. At a molecular level. structural understanding of h ow certain antisense RNAs control replication and stability functions is al most complete. Control circuits linking plasmid transfer functions to the s tatus of the bacterial population have been dissected, uncovering a complex and hierarchical organisation. Coordinate or global regulation of plasmid replication, transfer and stable maintenance functions is becoming apparent across a range of plasmid families.