Abstract
VqsR is a quorum-sensing (QS) transcriptional regulator which controls QS systems (las, rhl and pqs) by directly downregulating the expression of qscR in Pseudomonas 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.
Keywords:
LuxR; Pseudomonas aeruginosa; VqsR; quorum sensing.
MeSH terms
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Acyl-Butyrolactones / chemistry*
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Acyl-Butyrolactones / metabolism
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Amino Acid Sequence
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Bacterial Proteins / chemistry*
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Bacterial Proteins / genetics
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Bacterial Proteins / metabolism
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Binding Sites
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Cloning, Molecular
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Crystallography, X-Ray
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Escherichia coli / genetics
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Escherichia coli / metabolism
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Gene Expression
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Genetic Vectors / chemistry
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Genetic Vectors / metabolism
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Models, Molecular
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Protein Binding
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Protein Conformation, alpha-Helical
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Protein Conformation, beta-Strand
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Protein Folding
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Protein Interaction Domains and Motifs
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Protein Multimerization
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Pseudomonas aeruginosa / chemistry*
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Pseudomonas aeruginosa / metabolism
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Quorum Sensing / genetics
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Recombinant Fusion Proteins / chemistry
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Recombinant Fusion Proteins / genetics
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Recombinant Fusion Proteins / metabolism
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Repressor Proteins / chemistry*
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Repressor Proteins / genetics
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Repressor Proteins / metabolism
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Sequence Alignment
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Structural Homology, Protein
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Trans-Activators / chemistry
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Trans-Activators / genetics
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Trans-Activators / metabolism
Substances
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Acyl-Butyrolactones
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Bacterial Proteins
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Recombinant Fusion Proteins
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Repressor Proteins
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Trans-Activators
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LuxR autoinducer binding proteins