DEG analysis according to NarQ overexrpession in E. coli W WT, E. coli W NarQXLP deleted strain

Further analysis revealed that the histidine kinase activity of NarQ was essential for this phenotype, and NarQ enhanced import even in the absence of the canonical Nar two-component system. Transcriptome profiling under NarQ overexpression revealed a distinct set of membrane-associated genes—including acrD, mliC, and pgaABCD—that were transcriptionally upregulated as part of the NarQ regulatory response. Functional tests confirmed that overexpression of these genes enhanced 3-HP import, while their deletion in producing strains increased 3-HP titers by up to 21% compared with the control strain.

Together, these results establish NarQ as a regulator of a broader membrane-associated network that indirectly governs 3-HP reuptake. This study also provides a systematic framework for identifying import-related genes directly from genomic DNA, thereby advancing the development of more efficient microbial production platforms.