A transcription factor required for aerial hyphae formation on rich medium (PubMed:12100547, PubMed:12453210). Activates transcription of ramC. Might be part of a two-component regulatory system (PubMed:12453210). Binds the promoter of ramC (PubMed:12100547, PubMed:12453210). Non-phosphorylated protein cooperatively binds multiple sites in the ramC promoter. Has not been seen to autophosphorylate using the small molecule phosphodonors phosphoramidate, acetyl phosphate or carbamoyl phosphate (PubMed:16051268). Upon low expression suppresses the bald (bld, no aerial hyphae) phenotype of citA but not bldJ mutants; higher expression also suppresses the bldJ mutant as well as several other bld mutations, inducing SapB production even on media where SapB is normally not produced (PubMed:12453210). Expression of the ram locus (ramA, ramB and ramR) induces rapid aerial mycelium formation in S.lividans (PubMed:8206859). Overexpression suppresses the no aerial hyphae phenotype of a chaplin-negative strain, probably by inducing expression of SapB (PubMed:17462011). Overexpression of RamR show there are about 280 genes having at least a threefold increase or fourfold decrease in RNA abundance versus wild-type including gene cluster SCO4072-SCO4075 (PubMed:16925552). Homodimer, in the absence of phosphorylation. Transcription about 8-10 hours before aerial hyphae formation commences, peaks at 38 hours just before aerial hyphae formation starts, decreases rapidly and stops as sporulation commences about 70 hours. Not autoregulated. The N-terminal response regulatory domain is atypical as it does not have conserved residues usually found in these domains; it is required for both homodimerization and DNA-binding. The C-terminal domain does not bind DNA alone, nor does it form homodimers. At very high concentrations overexpression of the C-terminal domain has a dominant-negative effect on DNA-binding by the whole protein. May be phosphorylated by an unknown kinase, probably on Asp-56. Deletion of ramR leads to loss of aerial hyphae and sporulation on rich solid medium after 4 days growth; by 5 days aerial hyphae and RamC are expressed (PubMed:12100547, PubMed:12453210). Deletion on rich medium leads to an initially bald (bld, no aerial hyphae) phenotype; after 4 days develops a substantial aerial mycelium. Wild-type mycelium on minimal medium (PubMed:17462011). 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 (PubMed:17462011). It is uncertain if Met-1 or Met-4 is the initiator.