Mechanism of bacteriophage Mu DNA transposition

The temperate bacteriophage Mu is a giant transposon under the cloak of a virus (see Bukhari 1976 for previous discussion). It has genes needed for its replication and transposition, genes for head and tail morphogenesis, and an intricate system to control the various functions. In addition, it contains genes for some highly interesting fuctions such as gin, which is required for the flip-flop of the G segment, and mom, which is involved in DNA modifications, a function that is not yet clearly understood. In this paper we discuss the current status of the Mu integration problem based on the experiments done in our laboratory. These experiments have sustained the replication-integration hypothesis and have shown that the donor molecules containing Mu DNA physically interact with the target DNA during the transposition process.