This family consists of several bacterial and phage proteins, including GemA (also known as gp16) protein from Bacteriophage Mu. GemA is an early protein responsible for decreasing host DNA gyrase activity, that promotes DNA relaxation of bacterial host genome. Modulates the expression of various host genes probably controlled by supercoiling of their promoters. Host genes affected include DNA replication and cell division determinants [1]. This family also includes the Mu-like prophage FluMu protein gp16 from Haemophilus influenzae.

1: The GemA protein of phage Mu and the GyrB gyrase subunit of Escherichia coli: the search for targets and interactions leading to the reversion of Mu-induced mutations. Abbes C, Joseleau-Petit D, Liebart JC, D'Ari R, Sezonov G; Biochimie. 2001;83:261-267. PMID:11278077