pfam11393: T4BSS_DotI_IcmL (This model is not part of the current CDD release)
Type-IV b secretion system, inner-membrane complex component
IcmL contains two amphipathic beta-sheet regions, required for the pore-forming ability which may be related to the transfer of this protein into a host cell membrane. The icmL gene shows significant similarity to plasmid genes involved in conjugation however IcmL is thought to be required for macrophage killing. It is unknown whether conjugation plays a role in macrophage killing. This is a family of DotI/IcmL proteins of type IVb secretion systems, that reside in the inner-membrane. It carries a single transmembrane helix in the N-terminal conserved region, has an extra-periplasmic domain, and is conserved in all T4BSSs including I-type conjugation systems (TraM). DotI/IcmL (and DotJ) may form an inner membrane complex that associates with the core complex.
Jiyao W et al.(2023). "The conserved domain database in 2023.",