title: 16S-23S and 23S-5S intergenic spacer regions of Streptococcus thermophilus and Streptococcus salivarius, primary and secondary structure.
abstract: The 16S-23S intergenic spacer region (spacer region 1) of Streptococcus salivarius, S. thermophilus, and Lactococcus lactis subsp. cremoris and the 23S-5S intergenic spacer region (spacer region 2) of S. salivarius and L. lactis subsp. cremoris were sequenced and compared with the spacer regions 1 and 2 of other streptococci. A high degree of intraspecific conservation was observed for S. thermophilus and L. lactis, and very similar sequences were found for S. salivarius and S. thermophilus. Whereas spacer region 1 is highly conserved in the genus Streptococcus sensu-stricto, only the tRNA gene and the rRNA processing stems are highly conserved in the three genera: Streptococcus sensu-stricto, Lactococcus, and Enterococcus. The presence of a unique tRNA(Ala) gene without the 3' terminal CCA sequence seems to be a general feature of the streptococci spacer region 1. A secondary structure model was built to show the interaction between the spacer regions 1 and 2 of S. thermophilus and S. salivarius. The rapid evolution of spacer region 1 in streptococci is in part due to insertions and deletions of small RNA stem/loop structures.
authors.affiliation: Laboratoire d'Enzymologie et de Génie Génétique, Université de Nancy I, URA CNRS 457, Vandoeuvre-Les-Nancy, France.
authors.forename: M
authors.initials: M
authors.lastname: Nour
authors.forename: A
authors.initials: A
authors.lastname: Naimi
authors.forename: G
authors.initials: G
authors.lastname: Beck
authors.forename: C
authors.initials: C
authors.lastname: Branlant
mesh_terms: D001483:Base Sequence; D017124:Conserved Sequence; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics*; D013294:Lactococcus lactis / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics*; D012336:RNA, Ribosomal, 16S / Q000737:chemistry / Q000235:genetics*; D012338:RNA, Ribosomal, 23S / Q000737:chemistry / Q000235:genetics*; D012344:RNA, Transfer, Ala / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D013291:Streptococcus / Q000737:chemistry / Q000235:genetics*
chemical_list: D004275:DNA, Ribosomal; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012338:RNA, Ribosomal, 23S; D012344:RNA, Transfer, Ala