Widening functional boundaries of the σ54promoter Pu of Pseudomonas putida by defeating extant physiological constraints

2015 ◽  
Vol 11 (3) ◽  
pp. 734-742 ◽  
Author(s):  
Aitor de las Heras ◽  
Esteban Martínez-García ◽  
Maria Rosa Domingo-Sananes ◽  
Víctor de Lorenzo
Keyword(s):  
Pseudomonas Putida ◽  
Transcriptional Regulator ◽  
Physiological Constraints ◽  
Sigma 54

The functional boundaries of thePupromoter can be expanded by overproduction of both sigma-54 and the transcriptional regulator XylR.

scholarly journals A Set of Activators and Repressors Control Peripheral Glucose Pathways in Pseudomonas putida To Yield a Common Central Intermediate

2008 ◽  
Vol 190 (7) ◽  
pp. 2331-2339 ◽  
Author(s):  
Teresa del Castillo ◽  
Estrella Duque ◽  
Juan L. Ramos
Keyword(s):  
Glucose Metabolism ◽  
Pseudomonas Putida ◽  
Transcriptional Regulator ◽  
Transport Systems ◽  
Transcriptional Repressors ◽  
Periplasmic Space ◽  
Host Chromosome ◽  
Catabolic Enzymes ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Transcriptional Fusions

ABSTRACT Pseudomonas putida KT2440 channels glucose to the central Entner-Doudoroff intermediate 6-phosphogluconate through three convergent pathways. The genes for these convergent pathways are clustered in three independent regions on the host chromosome. A number of monocistronic units and operons coexist within each of these clusters, favoring coexpression of catabolic enzymes and transport systems. Expression of the three pathways is mediated by three transcriptional repressors, HexR, GnuR, and PtxS, and by a positive transcriptional regulator, GltR-2. In this study, we generated mutants in each of the regulators and carried out transcriptional assays using microarrays and transcriptional fusions. These studies revealed that HexR controls the genes that encode glucokinase/glucose 6-phosphate dehydrogenase that yield 6-phosphogluconate; the genes for the Entner-Doudoroff enzymes that yield glyceraldehyde-3-phosphate and pyruvate; and gap-1, which encodes glyceraldehyde-3-phosphate dehydrogenase. GltR-2 is the transcriptional regulator that controls specific porins for the entry of glucose into the periplasmic space, as well as the gtsABCD operon for glucose transport through the inner membrane. GnuR is the repressor of gluconate transport and gluconokinase responsible for the conversion of gluconate into 6-phosphogluconate. PtxS, however, controls the enzymes for oxidation of gluconate to 2-ketogluconate, its transport and metabolism, and a set of genes unrelated to glucose metabolism.

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