The kicA and kicB genes are found upstream of mukB. It has been suggested that the kicB gene encodes a killing factor and the kicA gene codes for a protein that suppresses the killing function of the kicB gene product [1]. It was also demonstrated that KicA and KicB can function as a post-segregational killing system, when the genes are transferred from the E. coli chromosome onto a plasmid [1].

1: New killing system controlled by two genes located immediately upstream of the mukB gene in Escherichia coli. Feng J, Yamanaka K, Niki H, Ogura T, Hiraga S; Mol Gen Genet 1994;243:136-147. PMID:7513784

2: The MukF subunit of Escherichia coli condensin: architecture and functional relationship to kleisins. Fennell-Fezzie R, Gradia SD, Akey D, Berger JM; EMBO J. 2005;24:1921-1930. PMID:15902272