title: Evidence that the essential response regulator YycF in Streptococcus pneumoniae modulates expression of fatty acid biosynthesis genes and alters membrane composition.
abstract: The YycFG two-component system, originally identified in Bacillus subtilis, is highly conserved among gram-positive bacteria with low G+C contents. In Streptococcus pneumoniae, the YycF response regulator has been reported to be essential for cell growth, but the signal to which it responds and the gene members of the regulon remain unclear. In order to investigate the role of YycFG in S. pneumoniae, we increased the expression of yycF by using a maltose-inducible vector and analyzed the genome-wide effects on transcription and protein expression during the course of yycF expression. The induction of yycF expression increased histidine kinase yycG transcript levels, suggesting an autoregulation of the yycFG operon. Evidence from both proteomic and microarray transcriptome studies as well as analyses of membrane fatty acid composition indicated that YycFG is involved in the regulation of fatty acid biosynthesis pathways and in determining fatty acid chain lengths in membrane lipids. In agreement with recent transcriptome data on pneumococcal cells depleted of YycFG, we also identified several other potential members of the YycFG regulon that are required for virulence and cell wall biosynthesis and metabolism.
authors.affiliation: Centro de Investigaciones Biológicas, Ramiro de Maeztu 9, 28040 Madrid, Spain.
authors.forename: M Luz
authors.initials: ML
authors.lastname: Mohedano
authors.forename: Karin
authors.initials: K
authors.lastname: Overweg
authors.forename: Alicia
authors.initials: A
authors.lastname: de la Fuente
authors.forename: Mark
authors.initials: M
authors.lastname: Reuter
authors.forename: Silvia
authors.initials: S
authors.lastname: Altabe
authors.forename: Francis
authors.initials: F
authors.lastname: Mulholland
authors.forename: Diego
authors.initials: D
authors.lastname: de Mendoza
authors.forename: Paloma
authors.initials: P
authors.lastname: López
authors.forename: Jerry M
authors.initials: JM
authors.lastname: Wells
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism*; D005227:Fatty Acids / Q000096:biosynthesis*; D015964:Gene Expression Regulation, Bacterial; D046228:Microarray Analysis; D040901:Proteomics; D015398:Signal Transduction; D013296:Streptococcus pneumoniae / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D005227:Fatty Acids; C119939:YycF protein, Bacteria