Final answer:
The protein with both nuclease and helicase activity, which is enhanced by TraY and IHF, is typically identified as the relaxosome component TraI in 'Escherichia coli'. However, the exact protein is not explicitly mentioned in the provided references.
Step-by-step explanation:
The protein that has both nuclease and helicase (ATP) activity, and whose function is enhanced by TraY and IHF, is not explicitly mentioned in the provided reference information. However, typically in bacterial conjugation, a protein complex known as the 'relaxosome' is responsible for the initiation of plasmid DNA transfer. In Escherichia coli, the protein TraI is a part of this complex and exhibits both nuclease and helicase activities, which are necessary for processing the plasmid DNA during transfer. Its function is enhanced by the accessory proteins TraY and integration host factor (IHF).