RT Journal Article
T1 GtrS and GltR form a two-component system: the central role of 2-ketogluconate in the expression of exotoxin A and glucose catabolic enzymes in Pseudomonas aeruginosa
A1 Daddaoua, Ab
A1 Molina Santiago, Carlos
A1 de la Torre, Jesús
A1 Krell, Tino
A1 Ramos, Juan Luis
K1 Pseudomonas aeruginosa
AB In the human pathogen Pseudomonas aeruginosa, the GltR regulator is required for glucose transport, whereas GtrS is a sensor kinase that plays a key role in mediating bacteria–host interaction and pathogen dissemination in the host. We show that GtrS and GltR form a two-component system that regulates the expression from the promoters Pedd/gap-1, PoprB and Pglk, which control the expression of genes involved in glucose metabolism and transport. In addition, the GtrS/GltR pair regulates the expression of toxA that encodes exotoxin A, the primary virulence factor. Microcalorimetry-based ligand screening of the recombinant GtrS ligand-binding domain revealed specific binding of 2-ketogluconate (2-KG) (KD = 5 μM) and 6-phosphogluconate (KD = 98 μM). These effectors accelerate GtrS autophosphorylation, with concomitant transphosphorylation of GltR leading to a three-fold increase in transcription. Surprisingly, in vivo a similar increase in expression from the above promoters was observed for the mutant deficient in GltR regardless of the presence of effectors. The GltR operator site was found to contain the consensus sequence 5′-tgGTTTTTc-3′. We propose that 2-KG is a key metabolite in the stringent transcriptional control of genes involved in virulence and glucose metabolism. We show that GltR is a transcriptional repressor that is released from DNA upon phosphorylation.
YR 2014
FD 2014-06-11
LK https://hdl.handle.net/10630/37445
UL https://hdl.handle.net/10630/37445
LA eng
NO Nucleic Acids Research, 2014, Vol. 42, No. 12 doi: 10.1093/nar/gku49
DS RIUMA. Repositorio Institucional de la Universidad de Málaga
RD 4 mar 2026