Framycetin

Framycetin (Neomycin B), an aminoglycoside antibiotic, is a potent RNase P cleavage activity inhibitor with a K_i of 35 μM. Framycetin competes for specific divalent metal ion binding sites in RNase P RNA. Framycetin inhibits hammerhead ribozyme with a K_i of 13.5 μM. Framycetin, a 5″-azido neomycin B precursor, binds the Drosha site in miR-525 and is used for hepatic encephalopathy and enteropathogenic E. coli infections^[1][2]. IC50 & Target: Ki: 35 μM (RNase P cleavage activity) and 13.5 μM (hammerhead ribozyme)^[1] In Vitro: The inhibition of RNase P RNA cleavage by Framycetin (Neomycin B; Fradiomycin B) is sensitive to pH and an increase in pH suppresses the inhibition in other systems^[1].
Framycetin targets the bacterial and human ribosome and affect translation. 5″-azido neomycin B and Framycetin selectively inhibit production of the mature miRNA, boosts a downstream protein, and inhibits invasion in HCC cell line^[2].
Framycetin binds to a structural rather than a sequence motif of the RNA. Its primary cognate target is the decoding site of the 16S rRNA, but it also binds to the Rev-responsive element in HIV-1, group I introns, and the hammerhead ribozyme, and thus inhibits their biological function^[3].
Framycetin induces misreading of the genetic code during translation and inhibits several ribozymes. The ribosomal target site is the 16 S rRNA 1400 to 1500 region^[4].