HflC and HflK help govern the stability of phage lambda cII protein, and thereby control the lysogenization frequency of phage lambda. HflKC inhibits the SecY-degrading activity of FtsH, possibly helping quality control of integral membrane proteins. HflC and HflK interact to form a complex, originally called HflA, now called HflKC. HflKC interacts with FtsH; complex formation is stimulated by ATP, and with YccA. Integration of this protein into the membrane depends on SecA, SecY and SecD but not on SecB or FtsY. HflK is unstable in the absence of HflC. Belongs to the band 7/mec-2 family. HflK subfamily. Was originally (PubMed:2973057) thought to be a protease. However, removal of residues '165-200' of complex member HflC (a ClpP-protease-like motif) does not alter the lysogenization process, and in vitro studies show no evidence of a protease activity for the isolated HflKC complex.