Articulospora sp. produces Art1, an inhibitor of bacterial histidine kinase.

A two-component system (TCS) comprising a histidine kinase (HK) sensor and a response regulator (RR) plays important roles in regulating the virulence of many pathogenic bacteria. We used a new screening method to isolate novel inhibitor Art1 against bacterial sensory HK from an acetone extract of solid cultures of Articulospora sp., an aquatic hypomycete. Art1 inhibited the ATP-dependent autophosphorylation of recombinant glutathione S-transferase-fusion protein SasA, a cyanobacterial HK, with an IC50 value of 9.5 microg/ml.