The eubacterial protein synthesis inhibitor pulvomycin interacts with archaeal elongation factor 1α from Sulfolobus solfataricus

► Archaeal Sulfolobus solfataricus elongation factor 1α interacts with the eubacterial antibiotic pulvomycin. ► The antibiotic increased the intrinsic GTPase of the enzyme but not that of its engineered forms. ► The effect on GTPase can be attributed to a reduced energy of activation of the hydrolytic reaction. ► The effects on fluorescence properties suggest conformational changes upon pulvomycin interaction. ► Pulvomycin renders SsEF-1α slightly more stable against chemical denaturation.