Figure 6.

Cys¹²⁸ and Cys²⁴⁴ are critical for the kinase activity of MBP–SlPDK1. The four Cys residues (Cys¹²⁸, Cys²¹⁴, Cys²⁴⁴, and Cys⁴⁶⁶) within SlPDK1 were mutated to Ser individually by site-directed mutagenesis to create four substituted versions of MBP–SlPDK1. The kinase assay was performed for the WT MBP–SlPDK1 and these four mutant fusion proteins using MBP–Adi3^K337Q as substrate in the absence (−) or presence (+) of 2 mm GSNO. Equal loading was shown by Coomassie Blue staining. This experiment was repeated three times with similar results.