The Role of RsmA in the Regulation of Swarming Motility in Serratia Marcescens

J Biomed Sci. Mar-Apr 2001;8(2):160-9. doi: 10.1007/BF02256408.


Swarming motility is a multicellular phenomenon comprising population migration across surfaces by specially differentiated cells. In Serratia marcescens, a network exists in which the flhDC flagellar regulatory master operon, temperature, nutrient status, and quorum sensing all contribute to the regulation of swarming motility. In this study, the rsmA (repressor of secondary metabolites) gene (hereafter rsmA(Sm)) was cloned from S. marcescens. The presence of multicopy, plasmid-encoded rsmA(Sm) expressed from its native promoter in S. marcescens inhibits swarming. Synthesis of N-acylhomoserine lactones, presumably by the product of smaI (a luxI homolog isolated from S. marcescens), was also inhibited. Knockout of rsmA(Sm) on the S. marcescens chromosome shortens the time before swarming motility begins after inoculation to an agar surface. A single copy of the chromosomal PrsmA(Sm)::luxAB reporter of rsmA(Sm) transcription was constructed. Using this reporter, the roles of the flhDC flagellar regulatory master operon, temperature and autoregulation in the control of rsmA(Sm) expression were determined. Our findings indicate that RsmA(Sm) is a component of the complex regulatory network that controls swarming.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Base Sequence
  • Cloning, Molecular
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Escherichia coli Proteins
  • Gene Deletion
  • Gene Expression Regulation, Bacterial
  • Locomotion*
  • Molecular Sequence Data
  • RNA-Binding Proteins*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism
  • Repressor Proteins / chemistry
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism*
  • Sequence Alignment
  • Serratia marcescens / genetics
  • Serratia marcescens / physiology*
  • Temperature
  • Trans-Activators / genetics
  • Trans-Activators / metabolism
  • Transformation, Bacterial


  • Bacterial Proteins
  • DNA-Binding Proteins
  • Escherichia coli Proteins
  • RNA-Binding Proteins
  • Recombinant Proteins
  • Repressor Proteins
  • RsmA protein, Erwinia carotovora
  • Trans-Activators
  • flhC protein, E coli
  • flhD protein, E coli

Associated data

  • GENBANK/AJ243121