text: The long flexible tail ejection system is used by some of these pathogens.
full_question: The long flexible tail ejection system is used by some of these pathogens. The N proteins of some of them form a complex with Nus that acts as an antiterminator. The proteins Gam, Exo, and Beta derived from one of these pathogens form the basis of the Red recombineering system. Some types use a cos site for DNA circularization. A namesake ATP-dependent DNA ligase is derived from a T-even type of these pathogens. Esther Lederberg discovered a species of them now used in specialized transduction. Their DNA was labeled with radioactive phosphorus in the Hershey-Chase experiment, which used the T2 species. For 10 points, name these viruses such as lambda that infect bacteria.
first_sentence: The long flexible tail ejection system is used by some of these pathogens.
raw_answer: bacteriophage [or coliphage; or Enterobacteria phage lambda; or lambda phage; or T4 phage]