FIG 1.

BagAB copurify as a heterodimer with ATPase activity. (A) The bagAB operon was cloned into pET24b(+), maintaining the original junction between the genes. The start codon of bagB (cyan) overlaps the stop codon of bagA (highlighted in red). The His₆ tag was fused to the C terminus of BagB. (B) Coomassie brilliant blue-stained SDS-PAGE gel of copurified BagAB-His₆. The molecular masses (standards are on the left in kilodaltons) of BagA and BagB are 36 and 41 kDa, respectively. (C) Size exclusion profile of BagAB-His₆ using a Superose 6 10/300 GL column, showing only one peak with a molecular mass around 80 kDa. Size standards are marked above the chromatographic profile. (D) ATPase activities of BagAB and its variants as determined by malachite green phosphate assay. Bovine serum albumin (BSA) was used as a negative control. Error bars represent standard deviations of three measurements.