The constant gene orf14.9, which belongs to the variable eps (exopolysaccharide) cluster, is involved in the cell growth of Streptococcus thermophilus.
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.
Tyvaert
Guillaume
G
Laboratoire de génétique et microbiologie, Université Henri Poincaré, Faculté des sciences et techniques, Vandoeuvre-lès-Nancy, France.
Morel
Catherine
C
Joly
Jean-Pierre
JP
Decaris
Bernard
B
Charron-Bourgoin
Florence
F
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
D011135:Polysaccharides, Bacterial