Thiol Redox Sensitivity of Two Key Enzymes of Heme Biosynthesis and Pentose Phosphate Pathways: Uroporphyrinogen Decarboxylase and Transketolase

Figure 8

Positioning of Cys622 in the structure of the Tkl1p molecule. Structure of Tkl1p with bound TPP, E4P, and Ca²⁺. (a) Subunit of homodimer, distance between cys622 and cys159 of active site from either subunit is too large for intradisulfide. (b) Interphase between subunits of homodimer, distance between cys622 of homodimers is 9.68 Å; Cys622 is close to both Thr and Arg residues, which can favour a thiolate and formation of sulfenic acid. Figures were prepared from structure PDB 1NGS using the free software DeepView [26].