Figure 2. SRT examples applied to biosynthesis and degradation pathway of a storage material.

(A) Schematic diagram illustrating the general concept of SRT, where E_a1, E_a2, and E_a3 are anabolic enzymes for biosynthesis (yellow arrows) of storage material, while E_c1, E_c2, and E_c3 are catabolic enzymes for degradation (green arrows). In this scheme, the defective enzyme is E_c2, while the target enzyme for SRT is E_a2. (B) Pathway of sphingolipid biosynthesis (yellow arrows) and degradation (green arrows). (C) Pathway of glycosaminoglycan biosynthesis (yellow arrows) and degradation (green arrows). For (B,C), blue letters denote enzymes proposed as SRT targets, to address the metabolic defects shown in red letters.