The absence of the luxS gene increases swimming motility and flagella synthesis in Escherichia coli K12

► This paper provides the first evidence that luxS deletion enhances swimming motility and flagella synthesis in Escherichia coli K12 based on motility, transcriptome, and scanning electron microscopy analyses. ► A conceptual genetic regulatory network underlying the increased flagella synthesis was constructed based on the transcriptome and network component analyses, and previously known regulatory relations. ► The genetic regulatory network suggests that the increased flagella synthesis and motility might be contributed to by increased flhDC transcription level and/or decreased c-di-GMP concentration in luxS-deficient E. coli. Despite the significant role of S-ribosylhomocysteinase (LuxS) in the activated methyl cycle pathway and quorum sensing, the connectivity between luxS and other cellular functions remains incomplete. Herein, we show that luxS deletion significantly increases swimming motility and flagella synthesis in Escherichia coli K12 using motility, transcriptome, and scanning electron microscopy assays. Further, based on the transcriptome and network component analyses, and known regulatory relations, we propose a conceptual genetic regulatory network underlying the increased flagella synthesis in response to luxS deletion.