scholarly journals Knot Formation Caused by Pseudomonas syringae subsp. savastanoi on Olive Plants Is hrp-Dependent

2004 ◽  
Vol 94 (5) ◽  
pp. 484-489 ◽  
Author(s):  
A. Sisto ◽  
M. G. Cipriani ◽  
M. Morea

The virulence of Pseudomonas syringae subsp. savastanoi, which causes hyperplastic symptoms (knots) on olive plants, is associated with secreted phytohormones. We identified a Tn5-induced mutant of P. syringae subsp. savastanoi that did not cause disease symptoms on olive plants although it was still able to produce phytohormones. In addition, the mutant failed to elicit a hypersensitive response in a nonhost plant. Molecular characterization of the mutant revealed that a single Tn5 insertion occurred within an open reading frame encoding a protein 92% identical to the HrcC protein of P. syringae pv. syringae. Moreover, sequence analysis revealed that the gene encoding the HrcC protein in P. syringae subsp. savastanoi was part of an operon that included five genes arranged as in other phytopathogenic bacteria. These results imply that hrp/hrc genes are functional in P. syringae subsp. savastanoi and that they play a key role in the pathogenicity of this plant pathogen.

2000 ◽  
Vol 66 (12) ◽  
pp. 5480-5483 ◽  
Author(s):  
Sean S. Dineen ◽  
Marite Bradshaw ◽  
Eric A. Johnson

ABSTRACT Boticin B is a heat-stable bacteriocin produced byClostridium botulinum strain 213B that has inhibitory activity against various strains of C. botulinum and related clostridia. The gene encoding the bacteriocin was localized to a 3.0-kb HindIII fragment of an 18.8-kb plasmid, cloned, and sequenced. DNA sequencing revealed the boticin B structural gene,btcB, to be an open reading frame encoding 50 amino acids. A C. botulinum strain 62A transconjugant containing theHindIII fragment inserted into a clostridial shuttle vector expressed boticin B, although at much lower levels than those observed in C. botulinum 213B. To our knowledge, this is the first demonstration and characterization of a bacteriocin from toxigenic group I C. botulinum.


1994 ◽  
Vol 40 (5) ◽  
pp. 403-407 ◽  
Author(s):  
René De Mot ◽  
Istvan Nagy ◽  
Geert Schoofs ◽  
Jos Vanderleyden

Sequence analysis of a 5173-bp genomic fragment from the nocardioform actinomycete Rhodococcus sp. strain NI86/21 revealed the presence of two genes, eutB and eutC, encoding the putative homologues of the large and small subunits of the ethanolamine ammonia-lyase, respectively, from Salmonella typhimurium. This is the first report of the characterization of these genes in a Gram-positive species. Immediately upstream of eutB, a gene encoding a putative permease of the APC (amino acids, polyamines, choline) transporter family was located. At present, no other Gram-positive members of this permease family are known. The translational coupling of these eut genes suggests an operon-like organization of the ethanolamine genes in Rhodococcus species. A truncated open reading frame downstream of eutC contained an N-terminal motif characteristic of membrane-anchored lipoproteins.Key words: nocardioform actinomycete, cobalamin, APC transporter, membrane-anchored lipoprotein, Gram-positive bacterium.


1999 ◽  
Vol 181 (5) ◽  
pp. 1409-1414 ◽  
Author(s):  
Ana Peciña ◽  
Alberto Pascual ◽  
Antonio Paneque

ABSTRACT The alginate lyase-encoding gene (algL) ofAzotobacter chroococcum was localized to a 3.1-kbEcoRI DNA fragment that revealed an open reading frame of 1,116 bp. This open reading frame encodes a protein of 42.98 kDa, in agreement with the value previously reported by us for this protein. The deduced protein has a potential N-terminal signal peptide that is consistent with its proposed periplasmic location. The analysis of the deduced amino acid sequence indicated that the gene sequence has a high homology (90% identity) to the Azotobacter vinelandii gene sequence, which has very recently been deposited in the GenBank database, and that it has 64% identity to the Pseudomonas aeruginosa gene sequence but that it has rather low homology (15 to 22% identity) to the gene sequences encoding alginate lyase in other bacteria. The A. chroococcum AlgL protein was overproduced in Escherichia coli and purified to electrophoretic homogeneity in a two-step chromatography procedure on hydroxyapatite and phenyl-Sepharose. The kinetic and molecular parameters of the recombinant alginate lyase are similar to those found for the native enzyme.


1996 ◽  
Vol 40 (10) ◽  
pp. 2350-2355 ◽  
Author(s):  
J A Aínsa ◽  
C Martin ◽  
B Gicquel ◽  
R Gomez-Lus

A novel gene encoding an aminoglycoside 2'-N-acetyltransferase (AAC) was cloned from Mycobacterium fortuitum. DNA sequencing results identified an open reading frame that we have called aac(2')-Ib encoding a putative protein with a predicted molecular mass of 24,800 Da. The deduced AAC(2')-Ib protein showed homology to the AAC(2')-Ia from Providencia stuartii. This is the second member of a subfamily of AAC(2')-I enzymes to be identified. No homology was found with other acetyltransferases, including all of the AAC(3) and AAC(6') proteins. The aac(2')-Ib gene cloned in a mycobacterial plasmid and introduced in Mycobacterium smegmatis conferred resistance to gentamicin, tobramycin, dibekacin, netilmicin, and 6'-N-ethylnetilmicin. DNA hybridization with an intragenic probe of aac(2')-Ib showed that this gene was present in all 34 strains of M. fortuitum tested. The universal presence of the aac(2')-Ib gene in M. fortuitum was not correlated with any aminoglycoside resistance phenotype, suggesting that this gene may play a role in the secondary metabolism of the bacterium.


2000 ◽  
Vol 66 (6) ◽  
pp. 2631-2635 ◽  
Author(s):  
Naveen Gupta ◽  
Vanga Shiva Reddy ◽  
Sankar Maiti ◽  
Amit Ghosh

ABSTRACT Alkalophilic Bacillus sp. strain NG-27 produces a 42-kDa endoxylanase active at 70°C and at a pH of 8.4. The gene for this endoxylanase was cloned and sequenced. The gene contained one open reading frame of 1,215 bases. An active site characteristic of the family 10 β-glycanases was recognized between amino acids 303 and 313, with the active glutamate at position 310. Though highly thermostable, the enzyme contains no cysteine residue.


1999 ◽  
Vol 181 (18) ◽  
pp. 5876-5879 ◽  
Author(s):  
Deborah A. Hogan ◽  
Thomas A. Auchtung ◽  
Robert P. Hausinger

ABSTRACT The Saccharomyces cerevisiae open reading frame YLL057c is predicted to encode a gene product with 31.5% amino acid sequence identity to Escherichia coli taurine/α-ketoglutarate dioxygenase and 27% identity to Ralstonia eutropha TfdA, a herbicide-degrading enzyme. Purified recombinant yeast protein is shown to be an Fe(II)-dependent sulfonate/α-ketoglutarate dioxygenase. Although taurine is a poor substrate, a variety of other sulfonates are utilized, with the best natural substrates being isethionate and taurocholate. Disruption of the gene encoding this enzyme negatively affects the use of isethionate and taurine as sulfur sources byS. cerevisiae, providing strong evidence that YLL057c plays a role in sulfonate catabolism.


2007 ◽  
Vol 73 (6) ◽  
pp. 1736-1741 ◽  
Author(s):  
Shuo Zhang ◽  
Eiji Sakuradani ◽  
Sakayu Shimizu

ABSTRACT Molecular cloning of the gene encoding sterol Δ7 reductase from the filamentous fungus Mortierella alpina 1S-4, which accumulates cholesta-5,24-dienol (desmosterol) as the main sterol, revealed that the open reading frame of this gene, designated MoΔ7SR, consists of 1,404 bp and codes for 468 amino acids with a molecular weight of 53,965. The predicted amino acid sequence of MoΔ7SR showed highest homology of 51% with that of sterol Δ7 reductase (EC 1.3.1.21) from Xenopus laevis (African clawed frog). Heterologous expression of the MoΔ7SR gene in yeast Saccharomyces cerevisiae revealed that MoΔ7SR converts ergosta-5,7-dienol to ergosta-5-enol (campesterol) by the activity of Δ7 reductase. In addition, with gene silencing of MoΔ7SR gene by RNA interference, the transformant accumulated cholesta-5,7,24-trienol up to 10% of the total sterols with a decrease in desmosterol. Cholesta-5,7,24-trienol is not detected in the control strain. This indicates that MoΔ7SR is involved in desmosterol biosynthesis in M. alpina 1S-4. This study is the first report on characterization of sterol Δ7 reductase from a microorganism.


Parasitology ◽  
2005 ◽  
Vol 132 (1) ◽  
pp. 117-126 ◽  
Author(s):  
E. L. LJUNGGREN ◽  
K. BERGSTRÖM ◽  
D. A. MORRISON ◽  
J. G. MATTSSON

We have cloned a cDNA encoding a novel antigen from a Sarcoptes scabiei (Acari) cDNA library by immunoscreening with sera from S. scabiei-infected dogs. The antigen is encoded by a 2157 bp mRNA with a predicted open reading frame of 719 amino acids (molecular weight 79 kDa). Our sequence analysis identified the presence of a MADF domain in the N-terminus, and downstream of this domain there was a region of low sequence complexity. This latter region contained several blocks of triplets and quadruplets of polar amino acids (Asn, Gln and Ser), and these 3 amino acids represented 39·7% of all amino acids. The antigen was named Atypical Sarcoptes Antigen 1 (ASA1) since the MADF domain normally is found in proteins involved in transcriptional regulation. In addition, 15 out of 62 S. scabiei-infected dogs reacted with a purified recombinant version of ASA1 in Western blot analysis. With immunohistochemistry we could show that ASA1 is expressed throughout the parasite, and that IgG specific for ASA1 binds to the inside wall of the mite's burrow. To our knowledge, this is the first description of an antigen containing an MADF domain.


1998 ◽  
Vol 66 (11) ◽  
pp. 5576-5579 ◽  
Author(s):  
Fauzi S. Silbaq ◽  
Sang-Nae Cho ◽  
Stewart T. Cole ◽  
Patrick J. Brennan

ABSTRACT During DNA sequence analysis of cosmid L373 from theMycobacterium leprae genome, an open reading frame of 1.4 kb encoding a protein with some homology to the immunodominant 34-kDa protein of Mycobacterium paratuberculosis, but lacking significant serological activity, was detected. The DNA sequence predicted a signal peptide with a modified lipoprotein consensus sequence, but the protein proved to be devoid of lipid attachment.


Sign in / Sign up

Export Citation Format

Share Document