Analysis of promoter sequences from Lactobacillus and Lactococcus and their activity in several Lactobacillus species

McCracken, Andrea; Turner, Mark S.; Giffard, Philip M.; Hafner, Louise M.; Timms, Peter

doi:10.1007/s002030000159

Cited by 58 publications

(44 citation statements)

References 27 publications

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“…2b). The distance between the 210 regions and the transcriptional start sites determined was 6 nt for strains R1, R27, R37, R39 and R42, and 5 nt for strain R41, all of which fall within the range of 6.9±2.7 bp reported for some lactobacilli (McCracken et al, 2000). Moreover, the detected transcriptional start site coincided with that of L. casei 64H (Lac + ) (Alpert & Siebers, 1997).…”

Section: Transcriptional Analyses Of the Lactp Promoterssupporting

confidence: 68%

“…For class IV, V and VI revertants, a point mutation was found in the 210 (TATAAC), 210 (TAAACT) and 235 (TTGACA) boxes of the lacTp promoter, respectively. These latter promoter sequences were found to have greater homology with the consensus promoter sequence (235: TTgaca and 210: TAtAAT; T ¢75 %, T 60-74 %, t 40-59 %) reported for some lactobacilli (McCracken et al, 2000). Therefore, these point mutations can be regarded as promoter-up mutations, which will enhance the level of transcription of the lacTEGF operon and allow the metabolism of lactose.…”

Section: Discussionmentioning

confidence: 89%

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Specific point mutations in Lactobacillus casei ATCC 27139 cause a phenotype switch from Lac− to Lac+

Tsai

Chen

et al. 2009

Microbiology

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Lactose metabolism is a changeable phenotype in strains of Lactobacillus casei. In this study, we found that L. casei ATCC 27139 was unable to utilize lactose. However, when exposed to lactose as the sole carbon source, spontaneous Lac + clones could be obtained. A gene cluster (lacTEGF-galKETRM) involved in the metabolism of lactose and galactose in L. casei ATCC 27139 (Lac " ) and its Lac + revertant (designated strain R1) was sequenced and characterized. We found that only one nucleotide, located in the lacTEGF promoter (lacTp), of the two lac-gal gene clusters was different. The protein sequence identity between the lac-gal gene cluster and those reported previously for some L. casei (Lac + ) strains was high; namely, 96-100 % identity was found and no premature stop codon was identified. A single point mutation located within the lacTp promoter region was also detected for each of the 41 other independently isolated Lac + revertants of L. casei ATCC 27139. The revertants could be divided into six classes based on the positions of the point mutations detected. Primer extension experiments conducted on transcription from lacTp revealed that the lacTp promoter of these six classes of Lac + revertants was functional, while that of L. casei ATCC 27139 was not. Northern blotting experiments further confirmed that the lacTEGF operon of strain R1 was induced by lactose but suppressed by glucose, whereas no blotting signal was ever detected for L. casei ATCC 27139. These results suggest that a single point mutation in the lacTp promoter was able to restore the transcription of a fully functional lacTEGF operon and cause a phenotype switch from Lac " to Lac + for L. casei ATCC 27139.

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Section: Transcriptional Analyses Of the Lactp Promoterssupporting

confidence: 68%

Section: Discussionmentioning

confidence: 89%

Specific point mutations in Lactobacillus casei ATCC 27139 cause a phenotype switch from Lac− to Lac+

Tsai

Chen

et al. 2009

Microbiology

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“…5), and these are in good agreement with the consensus sequence of vegetative promoters identified in Lb. rhamnosus (McCracken et al, 2000). Conserved bases corresponding to the consensus AT-rich UP element (upstream enhancer element; Estrem et al, 1998) were Fig.…”

Section: Determination Of Transcriptional Start Sitesmentioning

confidence: 99%

Comparative analysis of the exopolysaccharide biosynthesis gene clusters from four strains of Lactobacillus rhamnosus

et al. 2005

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The exopolysaccharide (EPS) biosynthesis gene clusters of four Lactobacillus rhamnosus strains consist of chromosomal DNA regions of 18·5 kb encoding 17 ORFs that are highly similar among the strains. However, under identical conditions, EPS production varies considerably among these strains, from 61 to 1611 mg l−1. Fifteen genes are co-transcribed starting from the first promoter upstream of wzd. Nevertheless, five transcription start sites were identified by 5′-RACE PCR analysis, and these were associated with promoter sequences upstream of wzd, rmlA, welE, wzr and wzb. Six potential glycosyltransferase genes were identified that account for the assembly of the heptasaccharide repeat unit containing an unusually high proportion of rhamnose. Four genes involved in the biosynthesis of the sugar nucleotide precursor dTDP-l-rhamnose were identified in the EPS biosynthesis locus, which is unusual for lactic acid bacteria. These four genes are expressed from their own promoter (P2), as well as co-transcribed with the upstream EPS genes, resulting in coordinated production of the rhamnose precursor with the enzymes involved in EPS biosynthesis. This is believed to be the first report demonstrating that the sequence, original organization and transcription of genes encoding EPS production are highly similar among four strains of Lb. rhamnosus, and do not vary with the amount of EPS produced.

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“…The sequence of the 210 region (TATAAT) of P IRL appears to be the most conserved one among the three promoters studied, but the 235 region (CTGAGA) of P IRL was not conserved with the consensus TTGACA box. On the other hand, the 235 hexamer (TGTCTC) of P djun was less conserved, since only 1 bp matched the consensus TTGACA box (McCracken et al, 2000). However, a number of promoters have now been reported where the specific 235 regions are not required for transcription initiation (Bown et al, 1997;Chan et al, 1990).…”

Section: Discussionmentioning

confidence: 99%

Formation of an inverted repeat junction in the transposition of insertion sequence ISLC3 isolated from Lactobacillus casei

Chen

Tsai

et al. 2008

Microbiology

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An insertion sequence, ISLC3, of 1351 bp has been isolated from Lactobacillus casei. Formation of IS circles containing a 3 bp spacer (complete junction) or deletion of 25 bp at the left inverted repeat (IRL) between the abutted IS ends of the ISLC3 junction region (deleted junction) was also discovered in the lactobacilli and Escherichia coli system studied. We found that the promoter formed by the complete junction P jun was more active than that formed by the 25 bp deleted junction P djun or the indigenous promoter P IRL . The corresponding transcription start sites for both promoter P jun and P IRL as well as P djun were subsequently determined using a primer extension assay. The activity of transposase OrfAB of ISLC3 was also assayed using an in vitro system. It was found that this transposase preferred to cleave a single DNA strand at the IRR over the IRL end in the transposition process, suggesting that attack of one end by the other was oriented from IRR to IRL.

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Analysis of promoter sequences from Lactobacillus and Lactococcus and their activity in several Lactobacillus species

Cited by 58 publications

References 27 publications

Specific point mutations in Lactobacillus casei ATCC 27139 cause a phenotype switch from Lac− to Lac+

Specific point mutations in Lactobacillus casei ATCC 27139 cause a phenotype switch from Lac− to Lac+

Comparative analysis of the exopolysaccharide biosynthesis gene clusters from four strains of Lactobacillus rhamnosus

Formation of an inverted repeat junction in the transposition of insertion sequence ISLC3 isolated from Lactobacillus casei

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