title: The constant gene orf14.9, which belongs to the variable eps (exopolysaccharide) cluster, is involved in the cell growth of Streptococcus thermophilus.
abstract: In Streptococcus thermophilus, the eps clusters involved in exopolysaccharide (EPS) biosynthesis are very polymorphic, nevertheless they all contain a highly conserved sequence corresponding to that of orf14.9. This open reading frame (ORF) is transcribed in a reverse direction with respect to eps genes. Amino acid sequence analysis showed a possible transmembrane location of the putative Orf14.9 protein but did not permit a proposed function. Insertional mutants of orf14.9 were obtained in strains NST2280 and A054 of S. thermophilus. EPS yields of these mutants are similar to those of their respective wild strains, suggesting that orf14.9 does not modify the quantity of produced EPS. Growth parameter determination for wild strains and their respective mutants showed that orf14.9 is involved in the cell growth of S. thermophilus.
authors.affiliation: Laboratoire de génétique et microbiologie, Université Henri Poincaré, Faculté des sciences et techniques, Vandoeuvre-lès-Nancy, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Tyvaert
authors.forename: Catherine
authors.initials: C
authors.lastname: Morel
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Joly
authors.forename: Bernard
authors.initials: B
authors.lastname: Decaris
authors.forename: Florence
authors.initials: F
authors.lastname: Charron-Bourgoin
mesh_terms: D015152:Blotting, Northern; D002455:Cell Division / Q000235:genetics; D023061:Gene Order; D005798:Genes, Bacterial / Q000235:genetics*; D005810:Multigene Family / Q000235:genetics; D016366:Open Reading Frames / Q000235:genetics; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D048249:Streptococcus thermophilus / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics
chemical_list: D011135:Polysaccharides, Bacterial