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Promoter Identification and Transcription Analysis of Penicillin-Binding Protein Genes in Streptococcus pneumoniae R6

View Article: PubMed Central - PubMed

ABSTRACT

Penicillin-binding proteins (PBPs) are membrane-associated enzymes, which are involved in the last two steps of peptidoglycan biosynthesis, and some of them are key players in cell division. Furthermore, they are targets of β-lactams, the most widely used antibiotics. Nevertheless, very little is known about the expression and regulation of PBP genes. Using transcriptional mapping, we now determined the promoter regions of PBP genes from the laboratory strain Streptococcus pneumoniae R6 and examined the expression profile of these six promoters. The extended −10 region is highly conserved and complies with a σA-type promoter consensus sequence. In contrast, the −35 region is poorly conserved, indicating the possibility for differential PBP regulation. All PBP promoters were constitutively expressed and highly active during the exponential and early stationary growth phase. However, the individual expression of PBP promoters varied approximately fourfold, with pbp1a being the highest and pbp3 the lowest. Furthermore, the deletion of one nucleotide in the spacer region of the PBP3 promoter reduced pbp3 expression ∼10-fold. The addition of cefotaxime above the minimal inhibitory concentration (MIC) did not affect PBP expression in the penicillin-sensitive R6 strain. No evidence for regulation of S. pneumoniae PBP genes was obtained.

No MeSH data available.


Related in: MedlinePlus

Organization of genomic regions containing Streptococcus pneumoniae R6 PBP genes. The coding regions and their directions of transcription are indicated by arrows and drawn in scale as indicated by the bar representing the size of 1 kb. PBP genes are shown in red, genes organized in operons with PBP genes are white, and flanking genes are imaged in gray. BOX and RUP elements are depicted in blue. Putative promoters are indicated by small black arrows and putative transcriptional terminators are shown as stem-loop structures. Spr numbers represent S. pneumoniae R6 genes. GI number of the S. pneumoniae R6 chromosome sequence in the NCBI Nucleotide database is GI:15902044; pbp1a (pbpA) identified in the NCBI Gene database (GeneID:934791), pbp1b (GeneID:934893), pbp2a (GeneID:933569), pbp2b (GeneID:933948), pbp2x (pbpX, GeneID:934744), and pbp3 (dacA, GeneID:934315). GI, GenInfo identifier; PBP, penicillin-binding protein.
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f1: Organization of genomic regions containing Streptococcus pneumoniae R6 PBP genes. The coding regions and their directions of transcription are indicated by arrows and drawn in scale as indicated by the bar representing the size of 1 kb. PBP genes are shown in red, genes organized in operons with PBP genes are white, and flanking genes are imaged in gray. BOX and RUP elements are depicted in blue. Putative promoters are indicated by small black arrows and putative transcriptional terminators are shown as stem-loop structures. Spr numbers represent S. pneumoniae R6 genes. GI number of the S. pneumoniae R6 chromosome sequence in the NCBI Nucleotide database is GI:15902044; pbp1a (pbpA) identified in the NCBI Gene database (GeneID:934791), pbp1b (GeneID:934893), pbp2a (GeneID:933569), pbp2b (GeneID:933948), pbp2x (pbpX, GeneID:934744), and pbp3 (dacA, GeneID:934315). GI, GenInfo identifier; PBP, penicillin-binding protein.

Mentions: The genes encoding PBPs in S. pneumoniae are localized at six distinct loci (Fig. 1) scattered throughout the genome. We searched for putative promoter regions and putative transcriptional terminators to define the genetic organization of S. pneumoniae R6 genomic regions containing the PBP genes.


Promoter Identification and Transcription Analysis of Penicillin-Binding Protein Genes in Streptococcus pneumoniae R6
Organization of genomic regions containing Streptococcus pneumoniae R6 PBP genes. The coding regions and their directions of transcription are indicated by arrows and drawn in scale as indicated by the bar representing the size of 1 kb. PBP genes are shown in red, genes organized in operons with PBP genes are white, and flanking genes are imaged in gray. BOX and RUP elements are depicted in blue. Putative promoters are indicated by small black arrows and putative transcriptional terminators are shown as stem-loop structures. Spr numbers represent S. pneumoniae R6 genes. GI number of the S. pneumoniae R6 chromosome sequence in the NCBI Nucleotide database is GI:15902044; pbp1a (pbpA) identified in the NCBI Gene database (GeneID:934791), pbp1b (GeneID:934893), pbp2a (GeneID:933569), pbp2b (GeneID:933948), pbp2x (pbpX, GeneID:934744), and pbp3 (dacA, GeneID:934315). GI, GenInfo identifier; PBP, penicillin-binding protein.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5036317&req=5

f1: Organization of genomic regions containing Streptococcus pneumoniae R6 PBP genes. The coding regions and their directions of transcription are indicated by arrows and drawn in scale as indicated by the bar representing the size of 1 kb. PBP genes are shown in red, genes organized in operons with PBP genes are white, and flanking genes are imaged in gray. BOX and RUP elements are depicted in blue. Putative promoters are indicated by small black arrows and putative transcriptional terminators are shown as stem-loop structures. Spr numbers represent S. pneumoniae R6 genes. GI number of the S. pneumoniae R6 chromosome sequence in the NCBI Nucleotide database is GI:15902044; pbp1a (pbpA) identified in the NCBI Gene database (GeneID:934791), pbp1b (GeneID:934893), pbp2a (GeneID:933569), pbp2b (GeneID:933948), pbp2x (pbpX, GeneID:934744), and pbp3 (dacA, GeneID:934315). GI, GenInfo identifier; PBP, penicillin-binding protein.
Mentions: The genes encoding PBPs in S. pneumoniae are localized at six distinct loci (Fig. 1) scattered throughout the genome. We searched for putative promoter regions and putative transcriptional terminators to define the genetic organization of S. pneumoniae R6 genomic regions containing the PBP genes.

View Article: PubMed Central - PubMed

ABSTRACT

Penicillin-binding proteins (PBPs) are membrane-associated enzymes, which are involved in the last two steps of peptidoglycan biosynthesis, and some of them are key players in cell division. Furthermore, they are targets of β-lactams, the most widely used antibiotics. Nevertheless, very little is known about the expression and regulation of PBP genes. Using transcriptional mapping, we now determined the promoter regions of PBP genes from the laboratory strain Streptococcus pneumoniae R6 and examined the expression profile of these six promoters. The extended −10 region is highly conserved and complies with a σA-type promoter consensus sequence. In contrast, the −35 region is poorly conserved, indicating the possibility for differential PBP regulation. All PBP promoters were constitutively expressed and highly active during the exponential and early stationary growth phase. However, the individual expression of PBP promoters varied approximately fourfold, with pbp1a being the highest and pbp3 the lowest. Furthermore, the deletion of one nucleotide in the spacer region of the PBP3 promoter reduced pbp3 expression ∼10-fold. The addition of cefotaxime above the minimal inhibitory concentration (MIC) did not affect PBP expression in the penicillin-sensitive R6 strain. No evidence for regulation of S. pneumoniae PBP genes was obtained.

No MeSH data available.


Related in: MedlinePlus