Question

For bacterial gene transfer via conjugation to occur, the host bacterium must possess a conjugative plasmid.

a) What are the processes that these plasmids control?

b) What are the special genes called that control this?

Please answer correctly and answer both questions.

Answer 1

In bacterial conjugation , there is direct cell to cell transfer of bacterial DNA. This is conferred by a conjugative plasmid in the donor bacteria.

a) The conjugative plasmid also known as Fertility factor F, has its own origin of transfer nic region (OriT-origin of transfer).This special region allows for cutting of one strand of double stranded circular plasmid DNA leading to rolling circle replication of plasmid into the recipient cell.

The conjugative plasmid allows the formation of pilus, a thin tubelike structure, that enables the donor cell to attach to recipient cell and transfer DNA.The plasmid allows for fusion of membrane between donor and recipient bacteria.

b) The conjugative plasmid has transfer genes tra and trb that faciliate DNA transfer to the recipient cell. It also has the pilin gene that allows for pilus formation. The tra locus also has genes that have regulatory genes for gene transfer as well as allow for attachment of proteins to the surface of recipient or F- bacteria enabling initiation of conjugation.