Figure S1 Purification and solution behavior of PaqCI

Panel a: SDS-PAGE gel of induced cell lysate and purification via metal affinity chromatography. Panel b: Size exclusion chromatographic elution of final purified PaqCI used for subsequent structural analyses. The protein elution profile is dark blue; underlying elution of molecular weight standards is light dashed grey. The expected peak elution volumes for an enzyme monomer (56 kD) or dimer (112 kD) are indicated with labeled arrows. The enzyme elutes as a multimeric complex that is consistent with an enzyme tetramer.