PMID:16385049

Citation	Herzberg, M, Kaye, IK, Peti, W and Wood, TK (2006) YdgG (TqsA) controls biofilm formation in Escherichia coli K-12 through autoinducer 2 transport. J. Bacteriol. 188:587-98
Abstract	YdgG is an uncharacterized protein that is induced in Escherichia coli biofilms. Here it is shown that deletion of ydgG decreased extracellular and increased intracellular concentrations of autoinducer 2 (AI-2); hence, YdgG enhances transport of AI-2. Consistent with this hypothesis, deletion of ydgG resulted in a 7,000-fold increase in biofilm thickness and 574-fold increase in biomass in flow cells. Also consistent with the hypothesis, deletion of ydgG increased cell motility by increasing transcription of flagellar genes (genes induced by AI-2). By expressing ydgG in trans, the wild-type phenotypes for extracellular AI-2 activity, motility, and biofilm formation were restored. YdgG is also predicted to be a membrane-spanning protein that is conserved in many bacteria, and it influences resistance to several antimicrobials, including crystal violet and streptomycin (this phenotype could also be complemented). Deletion of ydgG also caused 31% of the bacterial chromosome to be differentially expressed in biofilms, as expected, since AI-2 controls hundreds of genes. YdgG was found to negatively modulate expression of flagellum- and motility-related genes, as well as other known products essential for biofilm formation, including operons for type 1 fimbriae, autotransporter protein Ag43, curli production, colanic acid production, and production of polysaccharide adhesin. Eighty genes not previously related to biofilm formation were also identified, including those that encode transport proteins (yihN and yihP), polysialic acid production (gutM and gutQ), CP4-57 prophage functions (yfjR and alpA), methionine biosynthesis (metR), biotin and thiamine biosynthesis (bioF and thiDFH), anaerobic metabolism (focB, hyfACDR, ttdA, and fumB), and proteins with unknown function (ybfG, yceO, yjhQ, and yjbE); 10 of these genes were verified through mutation to decrease biofilm formation by 40% or more (yfjR, bioF, yccW, yjbE, yceO, ttdA, fumB, yjiP, gutQ, and yihR). Hence, it appears YdgG controls the transport of the quorum-sensing signal AI-2, and so we suggest the gene name tqsA.
Links	PubMed PMC1347309 Online version:10.1128/JB.188.2.587-598.2006
Keywords	Biofilms/growth & development; Biological Transport/genetics; Escherichia coli K12/physiology; Escherichia coli Proteins/genetics; Escherichia coli Proteins/physiology; Gene Deletion; Genes, Bacterial/genetics; Homoserine/analogs & derivatives; Homoserine/metabolism; Lactones/metabolism; Transcription, Genetic
edit table

Main Points of the Paper

Please summarize the main points of the paper.

Materials and Methods Used

Please list the materials and methods used in this paper (strains, plasmids, antibodies, etc).

Phenotype Annotations

See Help:AnnotationTable for details on how to edit this table.
<protect>

Phenotype of	Taxon Information	Genotype Information (if known)	Condition Information	OMP ID	OMP Term Name	ECO ID	ECO Term Name	Notes	Status
edit table

</protect>

References

See Help:References for how to manage references in omp dev.