scholarly journals Crystal Structure of the Quorum-sensing Protein TraM and Its Interaction with the Transcriptional Regulator TraR

2004 ◽  
Vol 279 (23) ◽  
pp. 24291-24296 ◽  
Author(s):  
Alessandro Vannini ◽  
Cinzia Volpari ◽  
Stefania Di Marco
Keyword(s):  
Crystal Structure ◽  
Quorum Sensing ◽  
Transcriptional Regulator

scholarly journals Revisiting the quorum-sensing hierarchy in Pseudomonas aeruginosa: the transcriptional regulator RhlR regulates LasR-specific factors

Microbiology ◽  
2009 ◽  
Vol 155 (3) ◽  
pp. 712-723 ◽  
Author(s):  
Valérie Dekimpe ◽  
Eric Déziel
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Transcriptional Regulator ◽  
Homoserine Lactone ◽  
The Other ◽  
Virulence Determinants ◽  
Late Stationary Phase ◽  
Regulatory Systems ◽  
Specific Factors

Pseudomonas aeruginosa uses the two major quorum-sensing (QS) regulatory systems las and rhl to modulate the expression of many of its virulence factors. The las system is considered to stand at the top of the QS hierarchy. However, some virulence factors such as pyocyanin have been reported to still be produced in lasR mutants under certain conditions. Interestingly, such mutants arise spontaneously under various conditions, including in the airways of cystic fibrosis patients. Using transcriptional lacZ reporters, LC/MS quantification and phenotypic assays, we have investigated the regulation of QS-controlled factors by the las system. Our results show that activity of the rhl system is only delayed in a lasR mutant, thus allowing the expression of multiple virulence determinants such as pyocyanin, rhamnolipids and C4-homoserine lactone (HSL) during the late stationary phase. Moreover, at this stage, RhlR is able to overcome the absence of the las system by activating specific LasR-controlled functions, including production of 3-oxo-C12-HSL and Pseudomonas quinolone signal (PQS). P. aeruginosa is thus able to circumvent the deficiency of one of its QS systems by allowing the other to take over. This work demonstrates that the QS hierarchy is more complex than the model simply presenting the las system above the rhl system.

scholarly journals Crystal structure ofPseudomonas aeruginosaRsaL bound to promoter DNA reaffirms its role as a global regulator involved in quorum-sensing

2016 ◽  
Vol 45 (2) ◽  
pp. 699-710 ◽  
Author(s):  
Huaping Kang ◽  
Jianhua Gan ◽  
Jingru Zhao ◽  
Weina Kong ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Quorum Sensing ◽  
Global Regulator ◽  
Promoter Dna

scholarly journals Crystal structure of the N-terminal domain of VqsR fromPseudomonas aeruginosaat 2.1 Å resolution

2017 ◽  
Vol 73 (7) ◽  
pp. 431-436
Author(s):  
Qing He ◽  
Kang Wang ◽  
Tiantian Su ◽  
Feng Wang ◽  
Lichuan Gu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Sequence Similarity ◽  
Transcriptional Regulator ◽  
Binding Domain ◽  
Structural Comparison ◽  
Homoserine Lactones ◽  
Terminal Domain ◽  
C Terminus ◽  
Common Motif ◽  
The Common

VqsR is a quorum-sensing (QS) transcriptional regulator which controls QS systems (las,rhlandpqs) by directly downregulating the expression ofqscRinPseudomonas aeruginosa. As a member of the LuxR family of proteins, VqsR shares the common motif of a helix–turn–helix (HTH)-type DNA-binding domain at the C-terminus, while the function of its N-terminal domain remains obscure. Here, the crystal structure of the N-terminal domain of VqsR (VqsR-N; residues 1–193) was determined at a resolution of 2.1 Å. The structure is folded into a regular α–β–α sandwich topology, which is similar to the ligand-binding domain (LBD) of the LuxR-type QS receptors. Although their sequence similarity is very low, structural comparison reveals that VqsR-N has a conserved enclosed cavity which could recognize acyl-homoserine lactones (AHLs) as in other LuxR-type AHL receptors. The structure suggests that VqsR could be a potential AHL receptor.

scholarly journals The Cyclic AMP Receptor Protein Regulates Quorum Sensing and Global Gene Expression in Yersinia pestis during Planktonic Growth and Growth in Biofilms

mBio ◽  
2019 ◽  
Vol 10 (6) ◽  
Author(s):  
Jeremy T. Ritzert ◽  
George Minasov ◽  
Ryan Embry ◽  
Matthew J. Schipma ◽  
Karla J. F. Satchell
Keyword(s):  
Gene Expression ◽  
Quorum Sensing ◽  
Carbon Source ◽  
Cyclic Amp ◽  
Yersinia Pestis ◽  
Carbon Sources ◽  
Transcriptional Regulator ◽  
Receptor Protein ◽  
Content Type ◽  
Bacterial Physiology

ABSTRACT Cyclic AMP (cAMP) receptor protein (Crp) is an important transcriptional regulator of Yersinia pestis. Expression of crp increases during pneumonic plague as the pathogen depletes glucose and forms large biofilms within lungs. To better understand control of Y. pestis Crp, we determined a 1.8-Å crystal structure of the protein-cAMP complex. We found that compared to Escherichia coli Crp, C helix amino acid substitutions in Y. pestis Crp did not impact the cAMP dependency of Crp to bind DNA promoters. To investigate Y. pestis Crp-regulated genes during plague pneumonia, we performed RNA sequencing on both wild-type and Δcrp mutant bacteria growing in planktonic and biofilm states in minimal media with glucose or glycerol. Y. pestis Crp was found to dramatically alter expression of hundreds of genes in a manner dependent upon carbon source and growth state. Gel shift assays confirmed direct regulation of the malT and ptsG promoters, and Crp was then linked to Y. pestis growth on maltose as a sole carbon source. Iron regulation genes ybtA and fyuA were found to be indirectly regulated by Crp. A new connection between carbon source and quorum sensing was revealed as Crp was found to regulate production of acyl-homoserine lactones (AHLs) through direct and indirect regulation of genes for AHL synthetases and receptors. AHLs were subsequently identified in the lungs of Y. pestis-infected mice when crp expression was highest in Y. pestis biofilms. Thus, in addition to the well-studied pla gene, other Crp-regulated genes likely have important functions during plague infection. IMPORTANCE Bacterial pathogens have evolved extensive signaling pathways to translate environmental signals into changes in gene expression. While Crp has long been appreciated for its role in regulating metabolism of carbon sources in many bacterial species, transcriptional profiling has revealed that this protein regulates many other aspects of bacterial physiology. The plague pathogen Y. pestis requires this global regulator to survive in blood, skin, and lungs. During disease progression, this organism adapts to changes within these niches. In addition to regulating genes for metabolism of nonglucose sugars, we found that Crp regulates genes for virulence, metal acquisition, and quorum sensing by direct or indirect mechanisms. Thus, this single transcriptional regulator, which responds to changes in available carbon sources, can regulate multiple critical behaviors for causing disease.

scholarly journals Crystal Structure of the Sugar Binding Domain of the Archaeal Transcriptional Regulator TrmB

2006 ◽  
Vol 281 (16) ◽  
pp. 10976-10982 ◽  
Author(s):  
Michael Krug ◽  
Sung-Jae Lee ◽  
Kay Diederichs ◽  
Winfried Boos ◽  
Wolfram Welte
Keyword(s):  
Crystal Structure ◽  
Transcriptional Regulator ◽  
Binding Domain ◽  
Sugar Binding

Crystal structure of YfiR, an unusual TetR/CamR-type putative transcriptional regulator from Bacillus subtilis

2006 ◽  
Vol 65 (1) ◽  
pp. 255-257 ◽  
Author(s):  
Shyamala S. Rajan ◽  
Xiaojing Yang ◽  
Ludmilla Shuvalova ◽  
Frank Collart ◽  
Wayne F. Anderson
Keyword(s):  
Crystal Structure ◽  
Bacillus Subtilis ◽  
Transcriptional Regulator

scholarly journals The Transcriptional Regulator VqmA Increases Expression of the Quorum-Sensing Activator HapR in Vibrio cholerae

2006 ◽  
Vol 188 (7) ◽  
pp. 2446-2453 ◽  
Author(s):  
Zhi Liu ◽  
Ansel Hsiao ◽  
Adam Joelsson ◽  
Jun Zhu
Keyword(s):  
Quorum Sensing ◽  
Vibrio Cholerae ◽  
Diarrheal Disease ◽  
Constitutive Expression ◽  
Physiological Role ◽  
Transcriptional Regulator ◽  
Protease Production ◽  
Dependent Manner ◽  
Cell Densities

ABSTRACT Vibrio cholerae is the causative agent of the severe diarrheal disease cholera. A number of environmental stimuli regulate virulence gene expression in V. cholerae, including quorum-sensing signals. At high cell densities, quorum sensing in V. cholerae invokes a series of signal transduction pathways in order to activate the expression of the master regulator HapR, which then represses the virulence regulon and biofilm-related genes and activates protease production. In this study, we identified a transcriptional regulator, VqmA (VCA1078), that activates hapR expression at low cell densities. Under in vitro inducing conditions, constitutive expression of VqmA represses the virulence regulon in a HapR-dependent manner. VqmA increases hapR transcription as measured by the activity of the hapR-lacZ reporter, and it increases HapR production as measured by Western blotting. Using a heterogenous luxCDABE cosmid, we found that VqmA stimulates quorum-sensing regulation at lower cell densities and that this stimulation bypasses the known LuxO-small-RNA regulatory circuits. Furthermore, we showed that VqmA regulates hapR transcription directly by binding to its promoter region and that expression of vqmA is cell density dependent and autoregulated. The physiological role of VqmA is also discussed.

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