Positive regulation of <i>Bacillus subtilis sigD</i> by C‐terminal truncated LacR at translational level

Ogura, Mitsuo; Hirao, Shigeharu; Ohshiro, Yasuhiro; Takano, Teruo

doi:10.1016/s0014-5793(99)01022-4

Cited by 3 publications

(2 citation statements)

References 37 publications

(53 reference statements)

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“…4). It encodes a transcriptional regulator that functions in the negative regulation of the b-galactosidase gene (lacA) as well as in the positive regulation of sigD in B. subtilis (Ogura et al 1999). Although a putative rho-independent transcription terminator is located downstream of the yvfI coding region (Kunst et al 1997), the lacR gene be function in regulating bacilysin activity and thus the observed loss of bacilysin production could actually be due to the polar effect of yvfI mutation on the downstream lacR gene.…”

Section: The Effect Of Yvfi and Lacr Null Mutations On The Bacilysin mentioning

confidence: 99%

The novel gene yvfI in Bacillus subtilis is essential for bacilysin biosynthesis

Köroğlu

Kurt-Gür

Unlü

et al. 2008

Antonie van Leeuwenhoek

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Using transposon mutagenesis in Bacillus subtilis PY79, three independent mutants defective in production of bacilysin were isolated. To identify the genes in these mutant loci affecting bacilysin biosynthesis, the inserted transposon and its flanking regions were cloned and sequenced from each mutant. Transposon insertions in these three mutants were found to be in the yvfI gene which encodes an unknown protein similar to GntR family transcriptional regulators. For further confirmation, deletion mutants were constructed in which nucleotides 196-314 of the yvfI gene were removed. All resulting yvfI (Delta196-314)::spc deletion mutants exhibited bacilysin-negative phenotypes, as in the case of the yvfI::Tn10::spc insertional mutants. The lacR gene, encoding a transcriptional regulator, resides immediately downstream from the yvfI gene. Therefore, an insertion mutation was created in the lacR gene to demonstrate that the bacilysin negative phenotype is actually due to the mutation in the yvfI gene and not a polar effect of yvfI mutation on the downstream gene. As expected, all resulting lacR mutant derivatives of PY79 still produced bacilysin.

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Section: The Effect Of Yvfi and Lacr Null Mutations On The Bacilysin mentioning

confidence: 99%

The novel gene yvfI in Bacillus subtilis is essential for bacilysin biosynthesis

Köroğlu

Kurt-Gür

Unlü

et al. 2008

Antonie van Leeuwenhoek

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“…The two remaining isolates were tested to determine whether the ␤-galactosidase activity was derived from the yitJlacZ fusion rather than from expression of lacA, a cryptic ␤-galactosidase gene carried on the B. subtilis chromosome (26). The yitJ-lacZ fusion in these isolates was replaced with a neomycin resistance gene cassette by homologous recombination, and the resulting colonies were screened for lacZ expression.…”

Section: Vol 188 2006 B Subtilis Sam Synthetase Mutant 3675mentioning

confidence: 99%

Identification of a Mutation in the Bacillus subtilis S -Adenosylmethionine Synthetase Gene That Results in Derepression of S-Box Gene Expression

et al. 2006

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Genes in the S-box family are regulated by binding of S-adenosylmethionine (SAM) to the 5 region of the mRNA of the regulated gene. SAM binding was previously shown to promote a rearrangement of the RNA structure that results in premature termination of transcription in vitro and repression of expression of the downstream coding sequence. The S-box RNA element therefore acts as a SAM-binding riboswitch in vitro. In an effort to identify factors other than SAM that could be involved in the S-box regulatory mechanism in vivo, we searched for trans-acting mutations in Bacillus subtilis that act to disrupt repression of S-box gene expression during growth under conditions where SAM pools are elevated. We identified a single mutant that proved to have one nucleotide substitution in the metK gene, encoding SAM synthetase. This mutation, designated metK10, resulted in a 15-fold decrease in SAM synthetase activity and a 4-fold decrease in SAM concentration in vivo. The metK10 mutation specifically affected S-box gene expression, and the increase in expression under repressing conditions was dependent on the presence of a functional transcriptional antiterminator element. The observation that the mutation identified in this search affects SAM production supports the model that the S-box RNAs directly monitor SAM in vivo, without a requirement for additional factors.The S-box regulatory system is used in low-GϩC grampositive organisms, including members of the Bacillus/Clostridium/Staphylococcus group, to regulate expression of genes involved in biosynthesis and transport of methionine and S-adenosylmethionine (SAM) (9)(10)(11)29). Genes in the S-box family exhibit a pattern of conserved sequence and structural elements in the 5Ј region of the mRNA, upstream of the start of the regulated coding sequence(s). These conserved elements include an intrinsic terminator and a competing antiterminator that can sequester sequences that otherwise form the 5Ј portion of the terminator helix; residues in the 5Ј region of the antiterminator can also pair with sequences located further upstream, and this pairing results in formation of a structure (the anti-antiterminator) that sequesters sequences necessary for formation of the antiterminator. The anti-antiterminator helix (helix 1) (Fig. 1) is located at the base of a complex structure comprised of helices 1 to 4. Genetic analyses of S-box leader RNAs supported the model that formation of the antiantiterminator and transcription termination occur during growth under conditions where methionine is abundant, while starvation for methionine results in destabilization of the anti-antiterminator, allowing antiterminator formation and readthrough of the transcription termination site (9). Mutational analysis also suggested that the helix 1 to 4 region is likely to be the target for binding of a negative regulatory factor or factors (9, 38) and that pairing between residues in the terminal loop of helix 2 and the region between helices 3 and 4 is important for termination during growth in h...

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Genetic Competence and Transformation in Oral Streptococci

Cvitkovitch

2001

Critical Reviews in Oral Biology & Medicine

111

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The oral streptococci are normally non-pathogenic residents of the human microflora. There is substantial evidence that these bacteria can, however, act as "genetic reservoirs" and transfer genetic information to transient bacteria as they make their way through the mouth, the principal entry point for a wide variety of bacteria. Examples that are of particular concern include the transfer of antibiotic resistance from oral streptococci to Streptococcus pneumoniae. The mechanisms that are used by oral streptococci to exchange genetic information are not well-understood, although several species are known to enter a physiological state of genetic competence. This state permits them to become capable of natural genetic transformation, facilitating the acquisition of foreign DNA from the external environment. The oral streptococci share many similarities with two closely related Gram-positive bacteria, S. pneumoniae and Bacillus subtilis. In these bacteria, the mechanisms of quorum-sensing, the development of competence, and DNA uptake and integration are well-characterized. Using this knowledge and the data available in genome databases allowed us to identify putative genes involved in these processes in the oral organism Streptococcus mutans. Models of competence development and genetic transformation in the oral streptococci and strategies to confirm these models are discussed. Future studies of competence in oral biofilms, the natural environment of oral streptococci, will be discussed.

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Positive regulation of Bacillus subtilis sigD by C‐terminal truncated LacR at translational level

Cited by 3 publications

References 37 publications

The novel gene yvfI in Bacillus subtilis is essential for bacilysin biosynthesis

The novel gene yvfI in Bacillus subtilis is essential for bacilysin biosynthesis

Identification of a Mutation in the Bacillus subtilis S -Adenosylmethionine Synthetase Gene That Results in Derepression of S-Box Gene Expression

Genetic Competence and Transformation in Oral Streptococci

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