scholarly journals Mutation studies of the gene encoding YuiC, a stationary phase survival protein in Bacillus subtilis

Author(s):  
Quay, D. H. X. ◽  
Qureshi, A. ◽  
Bhakta, S. ◽  
Keep, N. H.
2008 ◽  
Vol 191 (3) ◽  
pp. 1101-1105 ◽  
Author(s):  
Warawan Eiamphungporn ◽  
John D. Helmann

ABSTRACT Bacillus subtilis yabE encodes a predicted resuscitation-promoting factor/stationary-phase survival (Rpf/Sps) family autolysin. Here, we demonstrate that yabE is negatively regulated by a cis-acting antisense RNA which, in turn, is regulated by two extracytoplasmic function σ factors: σX and σM.


mBio ◽  
2019 ◽  
Vol 10 (5) ◽  
Author(s):  
Wayne L. Nicholson

ABSTRACT Bacillus subtilis cells can mount a number of responses to nutritional deprivation but ultimately either form dormant spores or enter a metabolically quiescent state. In a recent article (mBio 10:e01414-19, https://doi.org/10.1128/mBio.01414-19, 2019), R. Hashuel and S. Ben-Yehuda report on a novel means by which nutrient-starved B. subtilis cells escape from aging (days-old) colonies by accumulating mutations enabling them to continue growth under nutrient-limited conditions. They postulate that such a strategy may be a major factor determining the dynamics of bacterial populations in natural environments.


2008 ◽  
Vol 74 (22) ◽  
pp. 6832-6838 ◽  
Author(s):  
Wayne L. Nicholson

ABSTRACT Bacillus subtilis is capable of producing 2,3-butanediol from acetoin by fermentation, but to date, the gene encoding the enzyme responsible, acetoin reductase/2,3-butanediol dehydrogenase (AR/BDH), has remained unknown. A search of the B. subtilis genome database with the amino acid sequences of functional AR/BDHs from Saccharomyces cerevisiae and Bacillus cereus resulted in the identification of a highly similar protein encoded by the B. subtilis ydjL gene. A knockout strain carrying a ydjL::cat insertion mutation was constructed, which (i) abolished 2,3-butanediol production in early stationary phase, (ii) produced no detectable AR or BDH activity in vitro, and (iii) accumulated the precursor acetoin in early stationary phase. The ydjL::cat mutation also affected the kinetics of lactate but not acetate production during stationary-phase cultivation with glucose under oxygen limitation. A very small amount of 2,3-butanediol was detected in very-late-stationary-phase (96-hour) cultures of the ydjL::cat mutant, suggesting the existence of a second gene encoding a minor AR activity. From the data, it is proposed that the major AR/BDH-encoding gene ydjL be renamed bdhA.


Biology ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 294
Author(s):  
Thunyarat Surasiang ◽  
Chalongrat Noree

Asparagine synthetase deficiency (ASD) has been found to be caused by certain mutations in the gene encoding human asparagine synthetase (ASNS). Among reported mutations, A6E mutation showed the greatest reduction in ASNS abundance. However, the effect of A6E mutation has not yet been tested with yeast asparagine synthetase (Asn1/2p). Here, we constructed a yeast strain by deleting ASN2 from its genome, introducing the A6E mutation codon to ASN1, along with GFP downstream of ASN1. Our mutant yeast construct showed a noticeable decrease of Asn1p(A6E)-GFP levels as compared to the control yeast expressing Asn1p(WT)-GFP. At the stationary phase, the A6E mutation also markedly lowered the assembly frequency of the enzyme. In contrast to Asn1p(WT)-GFP, Asn1p(A6E)-GFP was insensitive to changes in the intracellular energy levels upon treatment with sodium azide during the log phase or fresh glucose at the stationary phase. Our study has confirmed that the effect of A6E mutation on protein expression levels of asparagine synthetase is common in both unicellular and multicellular eukaryotes, suggesting that yeast could be a model of ASD. Furthermore, A6E mutation could be introduced to the ASNS gene of acute lymphoblastic leukemia patients to inhibit the upregulation of ASNS by cancer cells, reducing the risk of developing resistance to the asparaginase treatment.


1997 ◽  
Vol 43 (12) ◽  
pp. 1118-1125 ◽  
Author(s):  
Martine Aubert ◽  
Elisabeth Weber ◽  
Brigitte Gintz ◽  
Bernard Decaris ◽  
Keith F. Chater

The deduced product of the spa2 gene of Streptomyces ambofaciens is a homologue of RspA, involved in stationary-phase σs factor regulation in Escherichia coli. This suggests that Spa2 could play a part in stationary-phase-associated differentiation in S. ambofaciens. The disruption of spa2 led to reductions in aerial mycelial development and associated spore pigmentation. The mutant phenotype reverted to the wild-type phenotype when the disruption construct spontaneously excised. The spa2 disruption had no detectable effect on growth rates in different media or antibiotic production and resistance. When spa2 was placed on a multicopy plasmid, a severe defect in formation and pigmentation of aerial mycelium resulted. These results strongly suggest that Spa2 is involved in a complex manner in the morphological differentiation process.Key words: Streptomyces, differentiation, stationary-phase regulator.


2021 ◽  
Vol 9 (6) ◽  
pp. 1284
Author(s):  
Tatiana Ermi ◽  
Carmen Vallin ◽  
Ana Gabriela Regalado García ◽  
Moises Bravo ◽  
Ismaray Fernandez Cordero ◽  
...  

Transcription-induced mutagenic mechanisms limit genetic changes to times when expression happens and to coding DNA. It has been hypothesized that intrinsic sequences that have the potential to form alternate DNA structures, such as non-B DNA structures, influence these mechanisms. Non-B DNA structures are promoted by transcription and induce genome instability in eukaryotic cells, but their impact in bacterial genomes is less known. Here, we investigated if G4 DNA- and hairpin-forming motifs influence stationary-phase mutagenesis in Bacillus subtilis. We developed a system to measure the influence of non-B DNA on B. subtilis stationary-phase mutagenesis by deleting the wild-type argF at its chromosomal position and introducing IPTG-inducible argF alleles differing in their ability to form hairpin and G4 DNA structures into an ectopic locus. Using this system, we found that sequences predicted to form non-B DNA structures promoted mutagenesis in B. subtilis stationary-phase cells; such a response did not occur in growing conditions. We also found that the transcription-coupled repair factor Mfd promoted mutagenesis at these predicted structures. In summary, we showed that non-B DNA-forming motifs promote genetic instability, particularly in coding regions in stressed cells; therefore, non-B DNA structures may have a spatial and temporal mutagenic effect in bacteria. This study provides insights into mechanisms that prevent or promote mutagenesis and advances our understanding of processes underlying bacterial evolution.


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