SUMMARY: The siderophore pyochelin of Pseudomonas aeruginosa is derived from one molecule of salicylate and two molecules of cysteine. Two cotranscribed genes, pChEF8 encoding peptide synthetases have been identified and characterized. pchE was required for the conversion of salicylate to dihydroaeruginoate (Dha), the condensation product of salicylate and one cysteine residue and pchF was essential for the synthesis of pyochelin from Dha. The deduced PchE(156 kDa) and PchF (197 kDa) proteins had adenylation, thiolation and condensationkyclization motifs arranged as modules which are typical of those peptide synthetases forming thiazoline rings. The pchEF genes were coregulated with the pchDCBA operon, which provides enzymes for the synthesis (PchBA) and activation (PchD) of salicylate as well as a putative thioesterase (PchC). Expression of a translational pchf-'/acZ fusion was strictly dependent on the PchR regulator and was induced by extracellular pyochelin, the end product of the pathway. Iron replete conditions led t o Fur (ferric uptake regulator)-dependent repression of the pchE -laciZ fusion. A translational pchD-lacZ fusion was also positively regulated by PchR and pyochelin and repressed by Fur and iron. Thus, autoinduction by pyochelin (or ferric pyochelin) and repression by iron ensure a sensitive control of the pyochelin pathway in P. aeruginosa.
BartonH.A.,
JohnsonZ.,
CoxC.D.,
VasilA.I.,
VasilM.L.1996; Ferric uptake regulator mutants of Pseudomonas aeruginosa with distinct alterations in the iron-dependent repression of exotoxin A and siderophores in aerobic and micro-aerobic environments.. Mol Microbiol 21:1001–1017
BeardenS.W.,
FetherstonJ.D.,
PerryR.D.1997; Genetic organization of the yersiniabactin biosynthetic region and con-struction of avirulent mutants in Yersinia pestis.
. Infect Immun 65:1659–1668
BritiganB.E.,
RasmussenG.T.,
CoxC.D.1997; Augmentation of oxidant injury to human pulmonary epithelial cells by the Pseudomonas aeruginosa siderophore pyochelin.. Infect Immun 65:1071–1076
CalderwoodS.B.,
MekalanosJ.J.1987; Iron regulation of Shiga-like toxin expression in Escherichia coli is mediated by the fur locus.. J Bacteriol 169:4759–4764
CarmiR.,
CarmeliS.,
LevyE.,
GoughF.J.1994; ( + )-(S)- Dihydro-aeruginoic acid, an inhibitor of Septoria tritici and other phytopathogenic fungi and bacteria, produced by Pseudomonas fluorescens.
. J Nat Prod 57:1200–1205
CoyneM.J.JRGoldbergJ.B.1995; Cloning and characterization of the gene (rfc) encoding O-antigen polymerase of Pseudomonas aeruginosa PAOl.. Gene 167:81–86
CrosaJ.H.1997; Signal transduction and transcriptional and posttranscriptional control of iron-regulated genes in bacteria.. Microbiol Mol Biol Rev 61:319–336
CunliffeH.E.,
MerrimanT.R.,
LamontI.L.1995; Cloning and characterization of pvdS, a gene required for pyoverdine synthesis in Pseudomonas aeruginosa-. PvdS is probably an alternative sigma factor.. J Bacteriol 177:2744–2750
FarinhaM.A.,
KropinskiA.M.1990; High efficiency electroporation of Pseudomonas aeruginosa using frozen cell suspensions.. FEMS Microbiol Lett 58:221–225
GehringA.M.,
BradleyK.A.,
WalshC.T.1997; Enterobactin biosynthesis in Escherichia coli: isochorismate lyase (EntB) is a bifunctional enzyme that is phosphopantetheinylated by EntD and then acylated by EntE using ATP and 2,3-dihydroxybenzoate.. Biochemistry 36:8495–8503
GehringA.M.,
MoriI.,
WalshC.T.1998; Reconstitution and characterization of the Escherichia coli enterobactin synthetase from EntB, EntE and EntF.. Biochemistry 37:2648–2659
GuilvoutI.,
Mercereau-PuijalonO.,
BonnefoyS.,
PugsleyA.P.,
CarnielE.1993; High-Molecular-Weight Protein 2 of Yersinia enterocolitica is homologous to AngR of Vibrio anguillarum and belongs to a family of proteins involved in nonribosomal peptide synthesis.. J Bacteriol 175:5488–5504
HeinrichsD.E.,
PooleK.1993; Cloning and sequence analysis of a gene (pchR) encoding an AraC family activator of pyochelin and ferripyochelin receptor synthesis in Pseudomonas aeruginosa.
. J Bacterial 175:5882–5889
HeinrichsD.E.,
PooleK.1996; PchR, a regulator of ferripyochelin receptor gene (fptA) expression in Pseudomonas aeruginosa, functions both as an activator and as a repressor.. J Bacteriol 178:2586–2592
KuJ.,
MirmiraR.G.,
LiuL.,
SantiD.V.1997; Expression of a functional non-ribosomal peptide synthetase module in Escherichia coli by coexpression with a phosphopantetheinyl transferase.. Chem Biol 4:203–207
LeoniL.,
CiervoA.,
OrsiN.,
ViscaP.1996; Iron-regulated transcription of the pvdA gene in Pseudomonas aeruginosa: effect of Fur and PvdS on promoter activity.. J Bacteriol 178:2299–2313
LobockaM.,
HennigJ.,
WildJ.,
KlopotowskiT.1994; Organization and expression of the Escherichia coli K-12 dad operon encoding the smaller subunit of D-amino acid dehydrogenase and the catabolic alanine racemase.. J Bacteriol 176:1500–1510
McMorranB.J.,
MerrimanM.E.,
RombelI.T.,
LamontI.L.1996; Characterization of the pvdE gene which is required for pyoverdine synthesis in Pseudomonas aeruginosa.
. Gene 176:55–59
MeyerJ.M.1992; Exogenous siderophore-mediated iron uptake in Pseudomonas aeruginosa: possible involvement of porin OprF in iron translocation.. J Gen Microbiol 138:951–958
MeyerJ.M.,
AbdallahM.A.1978; The fluorescent pigment of Pseudomonas aeruginosa: biosynthesis, purification and physicochemical properties.. J Gen Microbiol 107:130–138
MiyazakiH.,
KatoH.,
NakazawaT.,
TsudaM.1995; A positive regulatory gene, pvdS, for expression of pyoverdin biosynthetic genes in Pseudomonas aeruginosa PAO.. Mol Gen Genet 248:17–24
OchsnerU.A.,
VasilA.I.,
VasilM.L.1995; Role of the ferric uptake regulator of Pseudomonas aeruginosa in the regulation of siderophores and exotoxin A expression: purification and activity on iron-regulated promoters.. J Bacteriol 177:7194–7201
RatledgeC.,
MachamL.P.,
BrownK.A.,
MarshallB.J.1974; Iron transport in Mycobacterium smegmatis: a restricted role for salicylic acid in the extracellular environment.. Biochim Biophys Acta 372:39–51
SchneiderA.,
MarahielM.A.1998; Genetic evidence for a role of thioesterase domains, integrated in or associated with peptide synthetases, in non-ribosomal peptide biosynthesis in Bacillus subtilis.
. Arch Microbiol 169:404–410
SerinoL.,
ReimmannC.,
ViscaP.,
BeyelerM.,
Della ChiesaV.,
HaasD.1997; Biosynthesis of pyochelin and dihydroaeruginoic acid requires the iron-regulated pchDCBA operon in Pseudomonas aeruginosa.
. J Bacteriol 179:248–257
SimonR.,
PrieferU.,
PühlerA.1983; A broad host range mobilization system for in vitro genetic engineering: transposon mutagenesis in Gram negative bacteria.. Bio-technology 1:784–790
StachelhausT.,
MarahielM.A.1995; Modular structure of peptide synthetases revealed by dissection of the multifunctional enzyme GrsA.. J Biol Chem 270:6163–6169
StintziA.,
MeyerJ.-M.,
PooleK.1997; The pvc gene cluster of Pseudomonas aeruginosa: role in the synthesis of the pyoverdin chromophore and regulation by the exotoxin A regulator PtxR. VI International Congress on Pseudomonas: Molecular Biology and Biotechnology.
. Madrid, Spain 1997
TomalskyM.E.,
ActisL.A.,
CrosaJ.H.1993; A single amino acid change in AngR, a protein encoded by pJMl-like virulence plasmids, results in hyperproduction of anguibactin.. Infect Immun 61:3228–3233
VoisardC.,
KeelC.,
HaasD.,
DéfagoG.1989; Cyanide production by Pseudomonas fluorescens helps suppress black root rot of tobacco under gnotobiotic conditions.. EMBO J 8:351–358
VoisardC.,
BullC.T.,
KeelC.,
LavilleJ.,
MaurhoferM.,
SchniderU.,
DéfagoG.,
HaasD.1994; Biocontrol of root diseases by Pseudomonas fluorescens CHAO: current concepts and experimental approaches.. In Molecular Ecology of Khizo- sphere Microorganisms pp. 67–89GaraF.O.,
DowlingD.N.,
BoestenB.
Edited by Weinheim: VCH;
YeR.W.,
HaasD.,
KaJ.O.,
KrishnapillaiV.,
ZimmermannA.,
BairdC.,
TiedjeJ.M.1995; Anaerobic activation of the entire denitrification pathway in Pseudomonas aeruginosa requires Anr, an analog of Fnr.. J Bacteriol 177:3606–3609