Gene PA2449 Is Essential for Glycine Metabolism and Pyocyanin Biosynthesis in Pseudomonas aeruginosa PAO1

Abstract

bMany pseudomonads produce redox active compounds called phenazines that function in a variety of biological processes. Phenazines are well known for their toxicity against non-phenazine-producing organisms, which allows them to serve as crucial biocontrol agents and virulence factors during infection. As for other secondary metabolites, conditions of nutritional stress or limitation stimulate the production of phenazines, but little is known of the molecular details underlying this phenomenon. Using a combination of microarray and metabolite analyses, we demonstrate that the assimilation of glycine as a carbon source and the biosynthesis of pyocyanin in Pseudomonas aeruginosa PAO1 are both dependent on the PA2449 gene. The inactivation of the PA2449 gene was found to influence the transcription of a core set of genes encoding a glycine cleavage system, serine hydroxymethyltransferase, and serine dehydratase. PA2449 also affected the transcription of several genes that are integral in cell signaling and pyocyanin biosynthesis in P. aeruginosa PAO1. This study sheds light on the unexpected relationship between the utilization of an unfavorable carbon source and the production of pyocyanin. PA2449 is conserved among pseudomonads and might be universally involved in the assimilation of glycine among this metabolically diverse group of bacteria.

Here’s to the Losers: Evolvable Residents Accelerate the Evolution of High-Fitness Invaders

“…Of the genes with mutations, only one is presently known to be important for L-serine metabolism. Ten mutations were found in gene PA2449, which is thought Residents Accelerate Invader Evolution 47 to be an enhancer-binding protein controlling transcription of genes in the L-glycine and L-serine metabolism pathway (Lundgren et al 2013). As PA2449 knockouts have impaired ability to metabolize L-serine, these mutations are not likely to cause loss of gene function.…”

Ethanolamine Catabolism in Pseudomonas aeruginosa PAO1 Is Regulated by the Enhancer-Binding Protein EatR (PA4021) and the Alternative Sigma Factor RpoN

“…At an OD 600 of 0.3, 0.5 ml of culture was treated with 1.0 ml of RNAprotect bacterial reagent (Qiagen), and RNA was then purified from the treated cells using the RNeasy kit (Qiagen) (25). Prior to cDNA synthesis, the purified RNA was checked for genomic DNA contamination by PCR designed to amplify the rplU gene (24,30,31). Following this quality check, reverse transcriptase reactions were conducted using 500 ng of purified RNA and the iScript cDNA synthesis kit (Bio-Rad).…”

Genetic Analysis of the Assimilation of C 5 -Dicarboxylic Acids in Pseudomonas aeruginosa PAO1

“…Each treatment was tested in triplicate, and galactosidase (LacZ) activity was measured by using the Miller assay as described previously (23). Recombinant P. aeruginosa and E. coli strains harboring pBRL485 were grown in nutrient broth no.…”

“…Microarray studies were performed by the Microarray Core Facility (Upstate Medical University, Syracuse, NY) by using P. aeruginosa PAO1 Affymetrix GeneChip arrays. Methods for conducting the microarray experiments, including data processing and statistical analysis, were done exactly as previously described (23).…”