This transposase is essential for integration, replication-transposition and excision of Bacteriophage Mu DNA. The crystal structure of the core domain of Mu transposase, MuA, exhibits that the first of two subdomains contains the active site and, despite very limited sequence homology, exhibits a striking similarity to the core domain of Human immunodeficiency virus 1 integrase. The enzymatic activity of MuA is known to be activated by formation of a DNA-bound tetramer of the protein [1].

1: Structure of the bacteriophage Mu transposase core: a common structural motif for DNA transposition and retroviral integration. Rice P, Mizuuchi K; Cell. 1995;82:209-220. PMID:7628012