Auxiliary glyceraldehyde-3-phosphate dehydrogenases shape central carbon metabolism in Pseudomonas putida.

GapC and GapD are substrate-specific auxiliary enzymes that contribute to redox balancing and metabolic module integration in Pseudomonas putida KT2440.

• Why it matters: Understanding the functional diversity of GapDH isoenzymes addresses the broader question of why bacteria maintain multiple redundant enzymes in central carbon metabolism, which is crucial for adapting to environmental changes.
• What they did: The study used targeted mutagenesis, growth phenotyping, biochemical analysis, proteomics, and metabolomics to characterize the roles of four GapDH isoenzymes, focusing on GapC and GapD's substrate-specific effects and network integration.
• The result: GapC and GapD provide secondary, substrate-dependent functions that support metabolic flexibility and redox balance, offering insights for metabolic engineering of carbon flux in Pseudomonas and related bacteria.