Tubercidin (7-Deazaadenosine) is an antibiotic obtained from Streptomyces tubercidicus. Tubercidin inhibits the growth of Streptococcus faecalis (8043) with an IC50 of 0.02 μM. Tubercidin inhibits polymerases by incorporating DNA or RNA, thereby inhibiting DNA replication, RNA and protein synthesis. Tubercidin is a weak inhibitor of adenosine phosphorylase, and interferes with the phosphorylation of adenosine and AMP. Tubercidin has antiviral activity.