Peptide carrier potentiality of Bacillus subtilis levansucrase

Petit‐Glatron, Marie‐Françoise; Chambert, Régis

doi:10.1099/00221287-138-6-1089

Cited by 9 publications

(9 citation statements)

References 23 publications

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“…The primers used are listed in Table 1. The transfer of plasmids pBS1, pBS2, pBS3, pBS4, pBS5, pBS6, pBS6M1, pBS6M2, pBS6M3, pBS6M4, and pBS6M5 into B. subtilis 168 was carried out by natural competence [32]. The new generated strains are listed and detailed in Table 2.…”

Section: Methodsmentioning

confidence: 99%

The Transcriptional Activator LdtR from ‘Candidatus Liberibacter asiaticus’ Mediates Osmotic Stress Tolerance

et al. 2014

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The causal agent of Huanglongbing disease, ‘Candidatus Liberibacter asiaticus’, is a non-culturable, gram negative, phloem-limited α-proteobacterium. Current methods to control the spread of this disease are still limited to the removal and destruction of infected trees. In this study, we identified and characterized a regulon from ‘Ca. L. asiaticus’ involved in cell wall remodeling, that contains a member of the MarR family of transcriptional regulators (ldtR), and a predicted L,D-transpeptidase (ldtP). In Sinorhizobium meliloti, mutation of ldtR resulted in morphological changes (shortened rod-type phenotype) and reduced tolerance to osmotic stress. A biochemical approach was taken to identify small molecules that modulate LdtR activity. The LdtR ligands identified by thermal shift assays were validated using DNA binding methods. The biological impact of LdtR inactivation by the small molecules was then examined in Sinorhizobium meliloti and Liberibacter crescens, where a shortened-rod phenotype was induced by growth in presence of the ligands. A new method was also developed to examine the effects of small molecules on the viability of ‘Ca. Liberibacter asiaticus’, using shoots from HLB-infected orange trees. Decreased expression of ldtRLas and ldtPLas was observed in samples taken from HLB-infected shoots after 6 h of incubation with the LdtR ligands. These results provide strong proof of concept for the use of small molecules that target LdtR, as a potential treatment option for Huanglongbing disease.

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Section: Methodsmentioning

confidence: 99%

The Transcriptional Activator LdtR from ‘Candidatus Liberibacter asiaticus’ Mediates Osmotic Stress Tolerance

et al. 2014

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“…The kinetics of the unfolding-refolding transition of both forms of levansucrase were followed by measuring the intrinsic fluorescence under two different conditions, as previously described (Petit-Glatron and Chambert, 1992). First, purified proteins were unfolded in 0.1 M potassium phosphate pH7 at 37 C. in the presence of EDTA.…”

Section: Unfolding-refolding Transition Mediated By Cs^' Of Wildtype mentioning

confidence: 99%

The contribution of the cell wall to a transmembrane calcium gradient could play a key role in Bacillus subtilis protein secretion

Petit‐Glatron

Grajcar

Munz

et al. 1993

Molecular Microbiology

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A weak Ca(2+)-binding site (Ka = 0.8 x 10(3) M-1, at pH 7) was identified in the mature part of levansucrase. An amino acid substitution (Thr-236-->Ile) in this site alters simultaneously the affinity for calcium, the folding transition and the efficiency of the secretion process of levansucrase. Moreover, the ability of the Bacillus subtilis cell wall to concentrate calcium ions present in the culture medium was studied. We confirm the results of Beveridge and Murray who showed that the concentration factor is about 100 to 120 times. This property preserves a high concentration of Ca2+ (> 2 mM) on the external side of the cytoplasmic membrane, even in the absence of further Ca2+ supplementation in the growth medium. Such local conditions allow the spontaneous unfolding-folding transition of levansucrase en route for secretion. Since several exocellular proteins of B. subtilis are calcium-binding proteins, we propose that the high concentration of calcium ion in the microenvironment of the cell wall may play a key role in the ultimate step of their secretion process.

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“…Transformation of B. subtilis was performed by natural competence. Integration in the sacA gene was verified by the inability to utilize sucrose as a carbon source on minimal medium (24).…”

Section: Methodsmentioning

confidence: 99%

LVIS553 Transcriptional Regulator Specifically Recognizes Novobiocin as an Effector Molecule

Pagliai

Gardner

Pande

et al. 2010

Journal of Biological Chemistry

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In this study we aimed to identify small molecules with high affinity involved in the allosteric regulation of LVIS553, a MarR member from Lactobacillus brevis ATCC367. Using high throughput screening, novobiocin was found to specifically bind LVIS553 with a K D ‫؍‬ 33.8 ؎ 2.9 M consistent with a biologically relevant ligand. Structure guided site-directed mutagenesis identified Lys 9 as a key residue in novobiocin recognition. The results found in vitro were correlated in vivo. An increased tolerance to the antibiotic was observed when LVIS553 and the downstream putative transport protein LVIS552 were either expressed in a low copy plasmid in L. brevis or as a single copy chromosomal insertion in Bacillus subtilis. We provide evidence that LVIS553 is involved in the specific regulation of a new mechanism of tolerance to novobiocin.

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Peptide carrier potentiality of Bacillus subtilis levansucrase

Cited by 9 publications

References 23 publications

The Transcriptional Activator LdtR from ‘Candidatus Liberibacter asiaticus’ Mediates Osmotic Stress Tolerance

The Transcriptional Activator LdtR from ‘Candidatus Liberibacter asiaticus’ Mediates Osmotic Stress Tolerance

The contribution of the cell wall to a transmembrane calcium gradient could play a key role in Bacillus subtilis protein secretion

LVIS553 Transcriptional Regulator Specifically Recognizes Novobiocin as an Effector Molecule

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