High frequency of lysogenization K (HflK) family; SPFH (stomatin, prohibitin, flotillin, and HflK/C) superfamily
This model characterizes proteins similar to prokaryotic HflK (High frequency of lysogenization K). Although many members of the SPFH (or band 7) superfamily are lipid raft associated, prokaryote plasma membranes lack cholesterol and are unlikely to have lipid raft domains. Individual proteins of this SPFH domain superfamily may cluster to form membrane microdomains which may in turn recruit multiprotein complexes. Escherichia coli HflK is an integral membrane protein which may localize to the plasma membrane. HflK associates with another SPFH superfamily member (HflC) to form an HflKC complex. HflKC interacts with FtsH in a large complex termed the FtsH holo-enzyme. FtsH is an AAA ATP-dependent protease which exerts progressive proteolysis against membrane-embedded and soluble substrate proteins. HflKC can modulate the activity of FtsH. HflKC plays a role in the decision between lysogenic and lytic cycle growth during lambda phage infection.