PQSPqsR

PQSPqsR is a putative bacterial transcriptional regulator associated with the PQS quorum-sensing system, named for its proposed interaction with the Pseudomonas Quinolone Signal (PQS). In hypothetical models, PQSPqsR would act as a PQS-responsive regulator that modulates transcription of genes involved in PQS synthesis and downstream virulence and social behaviors.

Proposed function: PQSPqsR would bind PQS directly or sense PQS-bound complexes, then bind promoter regions to regulate operons such as pqsABCDE and genes encoding virulence factors, biofilm formation, and antibiotic resistance. The regulator is typically depicted as belonging to the LysR- or related families of transcription factors, with an N-terminal DNA-binding domain and a C-terminal regulatory domain that could sense small-molecule signals.

Genomic context: in draft genome annotations, PQSPqsR is predicted to reside within or near PQS biosynthetic gene clusters. Its exact locus, adjacency to pqsABCDE, and operon structure vary across species, leading to uncertainty about its universal role.

Status: The existence and function of PQSPqsR are not well established in the literature. Some annotations conflating PQSPqsR with the known regulator PqsR (MvfR) exist, while others treat PQSPqsR as a proposed, unconfirmed regulator. Further experimental validation, such as DNA-binding assays and QS-regulon profiling, is needed.

See also: PQS, PqsR/MvfR, Pseudomonas aeruginosa, quorum sensing.