Figure 9.

The D2HGDH plays a dual role in l-serine biosynthesis and d-malate utilization of P. stutzeri. A, the coupling between D2HGDH and SerA makes the robust interconversion between d-2-HG, 2-KG, d-malate, and OAA to overcome the thermodynamic barrier of d-3-PG dehydrogenation and facilitate the biosynthetic process of l-serine. B, D2HGDH participates in external d-malate utilization (orange shading) and OAA and 2-KG regeneration in TCA cycle in vivo (green and blue shading) during l-serine synthesis. CIT, citrate; ICIT, isocitrate; SUC, succinate; MAL, l-malate; d-MT, d-malate.