Activity and substrate specificity of IMAC-purified recombinant Arabidopsis PFT and PGGT I. Left Panel: E. coli extracts before Co2+-IMAC, unbound proteins, and bound (IMAC-purified) proteins are shown. An E. coli protein at 42 kDa, which co-migrates with the PGGT I β-subunit is present at low levels in the purified PFT and PGGT I samples. Right Panel: quantitative activity data for purified PFT and PGGT I. The standard error of the mean is shown.