Probably involved in exporting SapB from the cell (Probable). Expression of the ram locus (ramA, ramB and ramR) induces rapid aerial mycelium formation in S.lividans (PubMed:8206859). Probably part of the ramC-ramS-ramA-ramB operon. Deletion of the ramC-ramS-ramA-ramB operon on rich medium leads to an initially bald (no aerial hyphae) phenotype; after 4 days develops a substantial aerial mycelium. Wild-type mycelium on minimal medium. No expression of SapB, normal expression of chaplins. A complete chaplin-negative plus ram-negative strain (deletion of ramR or the ramC-ramS-ramA-ramB operon) leads to the complete loss of robust aerial hyphae. Belongs to the ABC transporter superfamily.