SDS-PAGE of PA-CoA ligase protein fractions collected during the purification scheme. Lanes 1 and 7, molecular mass protein standards containing phosphorylase (97 kDa), bovine serum albumin (67 kDa), ovalbumin (45 kDa), lactate dehydrogenase (34 kDa), and carbonic anhydrase (29 kDa); lane 2, crude extract (supernatant after centrifugation at 100,000 × g, 130 μg of protein); lane 3, DEAE fraction (negative chromatography, 85 μg of protein); lane 4, DEAE fraction (positive chromatography, 60 μg of protein); lane 5, Q-Sepharose fraction (45 μg of protein); lane 6, reactive-green fraction (6 μg of protein); lane 8, hydroxyapatite fraction (5 μg of protein).