Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023241 (Legionella)
 6,990 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The lly (legiolysin) locus codes for a 39-kDa protein which confers hemolysis, pigment production, and fluorescence on recombinant Escherichia coli K-12 clones carrying the lly gene. The nucleotide sequences of the lly genes from two Legionella pneumophila isolates were determined. The lly loci exhibited identical nucleotide sequences. They contained open reading frames of 348 amino acid residues, encoding proteins with a deduced molecular mass of 38.9 kDa. N-terminal amino acid sequencing further confirmed that the Lly protein corresponds to the open reading frame sequenced. The amino acid sequence of the Lly protein exhibits a high degree of homology with the sequences of the MelA protein responsible for melanin production in the freshwater bacterium Shewanella colwelliana and the 4-hydroxyphenylpyruvate dioxygenase of Pseudomonas spp. 4-Hydroxyphenylpyruvate dioxygenase is involved in the degradation of aromatic amino acids in various organisms. An Lly-negative mutant of L. pneumophila Philadelphia I derivative JR32 and an Lly-positive transcomplementant were constructed. The Lly-negative mutant lost the ability to produce brown pigment and to confer fluorescence but retained hemolysis. Introduction of a plasmid carrying the lly locus restored pigment production and fluorescence. Intracellular survival of L. pneumophila in U937 macrophage-like cells and in Acanthamoeba castellanii was not affected by mutagenization of the lly locus.
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PMID:Sequence determination and mutational analysis of the lly locus of Legionella pneumophila. 811 44

A gene (vllY) encoding a novel hemolysin of Vibrio vulnificus CKM-1 has been cloned and sequenced. When the vllY gene was expressed in minicells, a unique peptide of approximately 40 kDa was identified. Subcellular fractionation of Escherichia coli cells carrying the vllY gene indicated that the VllY protein was distributed in both the cytoplasmic and the periplasmic fractions, with the notable ability to appear in the latter compartment. Nucleotide sequence analysis predicted a single open reading frame of 1,071 bp encoding a 357-amino acid polypeptide with an estimated pI of 5.02. The deduced amino acid sequence of VllY showed high similarity to the sequence of legiolysin, responsible for hemolysis, pigment production, and fluorescence in Legionella pneumophila. The enzyme also exhibited sequence homology to the MelA protein sequence of Shewanella colwelliana and the sequences of 4-hydroxyphenylpyruvate dioxygenase family proteins from various organisms. PCR screening and Southern blotting of V. vulnificus strains revealed that all of the 41 V. vulnificus clinical isolates contained vllY-like genes.
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PMID:Cloning and sequence analysis of a novel hemolysin gene (vllY) from Vibrio vulnificus. 932 48

To access the genetic and biochemical potential of soil microorganisms by culture-independent methods, a 24,546-member library in Escherichia coli with DNA extracted directly from soil had previously been constructed (M. R. Rondon, P. R. August, A. D. Bettermann, S. F. Brady, T. H. Grossman, M. R. Liles, K. A. Loiacono, B. A. Lynch, I. A. MacNeil, M. S. Osburne, J. Clardy, J. Handelsman, and R. M. Goodman, Appl. Environ. Microbiol. 66:2541-2547, 2000). Three clones, P57G4, P89C8, and P214D2, produced colonies with a dark brown melanin-like color. We fractionated the culture supernatant of P57G4 to identify the pigmented compound or compounds. Methanol extracts of the acid precipitate from the culture supernatant contained a red and an orange pigment. Structural analysis revealed that these were triaryl cations, designated turbomycin A and turbomycin B, respectively; both exhibited broad-spectrum antibiotic activity against gram-negative and gram-positive organisms. Mutagenesis, subcloning, and sequence analysis of the 25-kb insert in P57G4 demonstrated that a single open reading frame was necessary and sufficient to confer production of the brown, orange, and red pigments on E. coli; the predicted product of this sequence shares extensive sequence similarity with members of the 4-hydroxyphenylpyruvate dioxygenase (4HPPD) family of enzymes. Another member of the same family of genes, lly, which is required for production of the hemolytic pigment in Legionella pneumophila, also conferred production of turbomycin A and B on E. coli. We further demonstrated that turbomycin A and turbomycin B are produced from the interaction of indole, normally secreted by E. coli, with homogentisic acid synthesized by the 4HPPD gene products. The results demonstrate successful heterologous expression of DNA extracted directly from soil as a means to access previously uncharacterized small organic compounds, serving as an example of a chimeric pathway for the generation of novel chemical structures.
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PMID:Isolation of antibiotics turbomycin a and B from a metagenomic library of soil microbial DNA. 1220 Feb 79