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Two iron-regulated compounds have been found in acidified ethyl acetate extracts from culture supernatants of Pseudomonas aeruginosa and Pseudomonas cepacia type-strains. Synthesis of both compounds paralleled iron-deficient growth, and was repressed in the presence of 100 microM-FeCl3. Yields of these substances varied among different strains and attained(More)
Pyoverdines are a group of structurally related siderophores produced by fluorescent Pseudomonas species. Recent genomic and biochemical data have shed new light on the complex molecular steps of pyoverdine biogenesis and explained the chemical diversity of these compounds. In the opportunistic pathogen Pseudomonas aeruginosa, pyoverdine is necessary for(More)
The high-affinity siderophore salicylate is an intermediate in the biosynthetic pathway of pyochelin, another siderophore and chelator of transition metal ions, in Pseudomonas aeruginosa. The 2.5-kb region upstream of the salicylate biosynthetic genes pchBA was sequenced and found to contain two additional, contiguous genes, pchD and pchC, having the same(More)
The enzyme L-ornithine N5-oxygenase catalyzes the hydroxylation of L-ornithine (L-Orn), which represents an early step in the biosynthesis of the peptidic moiety of the fluorescent siderophore pyoverdin in Pseudomonas aeruginosa. A gene bank of DNA from P. aeruginosa PAO1 (ATCC 15692) was constructed in the broad-host-range cosmid pLAFR3 and mobilized into(More)
Pseudomonas aeruginosa synthesizes two siderophores, pyochelin and pyoverdin, characterized by widely different structures, physicochemical properties, and affinities for Fe(III). Titration experiments showed that pyochelin, which is endowed with a relatively low affinity for Fe(III), binds other transition metals, such as Cu(II), Co(II), Mo(VI), and(More)
The Escherichia coli chromosome contains two distantly located genes, gadA and gadB, which encode biochemically undistinguishable isoforms of glutamic acid decarboxylase (Gad). The Gad reaction contributes to pH homeostasis by consuming intracellular H(+) and producing gamma-aminobutyric acid. This compound is exported via the protein product of the gadC(More)
A variety of bacterial species secrete and take up chelating compounds that enable acquisition of iron (siderophores). It has become clear that a common feature in regulation of different iron acquisition systems is the involvement of alternative sigma factor proteins of the extracytoplasmic function (ECF) family. Two of these proteins, PvdS from(More)
A fraction of the nuclear estrogen receptor alpha (ERalpha) is localized to the plasma membrane region of 17beta-estradiol (E2) target cells. We previously reported that ERalpha is a palmitoylated protein. To gain insight into the molecular mechanism of ERalpha residence at the plasma membrane, we tested both the role of palmitoylation and the impact of E2(More)
The inventory of microorganisms responsible for biological deterioration of ancient paintings has become an integral part of restoration activities. Here, the microbial agent of rosy discoloration on medieval frescoes in the Crypt of the Original Sin (Matera, Italy) was investigated by a combination of microscopic, molecular and spectroscopic approaches.(More)
The siderophore pyoverdine (PVD) is a primary virulence factor of the human pathogenic bacterium Pseudomonas aeruginosa, acting as both an iron carrier and a virulence-related signal molecule. By exploring a number of P. aeruginosa candidate systems for PVD secretion, we identified a tripartite ATP-binding cassette efflux transporter, here named PvdRT-OpmQ,(More)