sven0915 is predicted to encode an Na/H ion antiporter. Divergently transcribed from sven0915 is sven0916, which is predicted to encode an efflux permease from the major facilitator superfamily, and it is presumably involved in CHL export. These efflux pumps are often involved in multidrug resistance, exporting toxic compounds to the out side of the cell, and they are usually driven by the energy stored in ion gradients to catalyze the transport of drugs a cross the membrane. Given their proximity in the CHL gene cluster, it is conceivable that sven0915 provides the energy required for sven0916 to export CHL outside the cell. The deletion of sven0915 reduced CHL production by 60% in the heterologous host S. coelicolor. Several homologues of sven0915 occur in the S. coelicolor M1152 genome, any one or more of which may partially compensate for the loss of Sven0915, thus allowing continued CHL export, although at lower levels, in the deletion mutant.