title: Regulatory roles of spnT, a novel gene located within transposon TnTIR.
abstract: The transposon TnTIR contains spnIR quorum-sensing system regulating sliding motility and the production of nuclease, biosurfactant, and prodigiosin in Serratia marcescens. Within TnTIR, a gene named spnT is upstream of and co-transcribed with spnI. SpnT is a cytoplasmic protein and its level peaks during early stationary phase. spnT over-expression resulted in inhibition of sliding motility and synthesis of prodigiosin, and biosurfactant similar to spnR. spnT but not spnR over-expression induced cell elongation and aberrant DNA replication in S. marcescens and Escherichia coli strains. In comparison with wild-type E. coli strain, over-expression of spnT in an E. coli priA and dnaC double-mutant strain did not lead to the aberrant cell morphology phenotypes, suggesting SpnT may act through the recombination-dependent DNA replication system. As spnT over-expression inhibited swarming but not swimming motility, SpnT may indirectly function as a negative regulator of surface-dependent migration and secondary metabolite production.
authors.affiliation: Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei, Taiwan, ROC.
authors.forename: Jun-Rong
authors.initials: JR
authors.lastname: Wei
authors.forename: Po-Chi
authors.initials: PC
authors.lastname: Soo
authors.forename: Yu-Tze
authors.initials: YT
authors.lastname: Horng
authors.forename: Shang-Chen
authors.initials: SC
authors.lastname: Hsieh
authors.forename: Yu-Huan
authors.initials: YH
authors.lastname: Tsai
authors.forename: Simon
authors.initials: S
authors.lastname: Swift
authors.forename: Helen
authors.initials: H
authors.lastname: Withers
authors.forename: Paul
authors.initials: P
authors.lastname: Williams
authors.forename: Hsin-Chih
authors.initials: HC
authors.lastname: Lai
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D002462:Cell Membrane / Q000235:genetics / Q000502:physiology; D002464:Cell Migration Inhibition; D004261:DNA Replication / Q000235:genetics; D004251:DNA Transposable Elements / Q000235:genetics*; D015536:Down-Regulation / Q000235:genetics; D029968:Escherichia coli Proteins / Q000235:genetics / Q000502:physiology; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D009068:Movement; D011353:Prodigiosin / Q000096:biosynthesis; D011956:Receptors, Cell Surface / Q000235:genetics / Q000502:physiology; D012706:Serratia marcescens / Q000235:genetics* / Q000502:physiology / Q000648:ultrastructure
chemical_list: D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D029968:Escherichia coli Proteins; D011956:Receptors, Cell Surface; C109287:Tir protein, E coli; D011353:Prodigiosin