scholarly journals New Mg2+-Dependent Oxytetracycline Resistance Determinant Tet 34 in Vibrio Isolates from Marine Fish Intestinal Contents

2002 ◽  
Vol 46 (5) ◽  
pp. 1550-1552 ◽  
Author(s):  
Lisa Nonaka ◽  
Satoru Suzuki

ABSTRACT A new oxytetracycline (OTC) resistance (Otcr) determinant, Tet 34, was cloned from chromosomal DNA of Vibrio sp. no. 6 isolated from intestinal contents of cultured yellowtail (Seriola quinqueradiata). The transformant, containing cloned Tet 34, could grow in broth containing 25 μg of drug per ml with 10 mM MgCl2. Tet 34 encoded an open reading frame (ORF) 154 amino acids long. The amino acid sequence of the ORF was homologous to sequences of several bacterial xanthine-guanine phosphoribosyltransferases (XPRTs), which act in purine nucleotide salvage synthesis. Mg2+ binding site residues and the active site were highly conserved in XPRT and the ORF of Tet 34. The results suggest that Tet 34 encodes a new Mg2+-dependent Otcr mechanism.

1998 ◽  
Vol 42 (2) ◽  
pp. 436-439 ◽  
Author(s):  
T. R. Walsh ◽  
W. A. Neville ◽  
M. H. Haran ◽  
D. Tolson ◽  
D. J. Payne ◽  
...  

ABSTRACT The Aeromonas veronii bv. sobria metallo-β-lactamase gene, imiS, was cloned. The imiS open reading frame extends for 762 bp and encodes a protein of 254 amino acids with a secreted modified protein of 227 amino acids and a predicted pI of 8.1. To confirm the predicted sequence, purified ImiS was digested and the resulting peptides were identified, yielding an identical sequence for ImiS, with 98% identity to CphA. Both possessed the putative active-site sequence Asn-Tyr-His-Thr-Asp at positions 88 to 92, which is unique to the Aeromonas metallo-β-lactamases.


Genome ◽  
1991 ◽  
Vol 34 (4) ◽  
pp. 644-651 ◽  
Author(s):  
Kenneth Koo ◽  
W. Dorsey Stuart

The gene product of the mtr locus of Neurospora crassa is required for the transport of neutral aliphatic and aromatic amino acids via the N system. We have previously cloned three cosmids containing Neurospora DNA that complement the mtr-6(r) mutant allele. The cloned DNAs were tightly linked to restriction fragment length polymorphisms that flank the mtr locus. A 2.9-kbp fragment from one cosmid was subcloned and found to complement the mtr-6(r) allele. Here we report the sequence of the fragment that hybridized to a poly(A)+ mRNA transcript of about 2300 nucleotides. We have identified an 845-bp open reading frame (ORF) having a 59-bp intron as the potential mtr ORF. S1 nuclease analysis of the transcript confirmed the transcript size and the presence of the intron. A second open reading frame was found upstream in the same reading frame as the mtr ORF and appears to be present in the mRNA transcript. The mtr ORF is predicted to encode a 261 amino acid polypeptide with a molecular mass of 28 613 Da. The proposed polypeptide exhibits six potential α-helical transmembrane domains with an average length of 23 amino acids, does not have a signal sequence, and contains amino acid sequence homologous to an RNA binding motif.Key words: sequence, membranes, ribonucleoprotein.


1986 ◽  
Vol 6 (5) ◽  
pp. 1711-1721
Author(s):  
E M McIntosh ◽  
R H Haynes

The dCMP deaminase gene (DCD1) of Saccharomyces cerevisiae has been isolated by screening a Sau3A clone bank for complementation of the dUMP auxotrophy exhibited by dcd1 dmp1 haploids. Plasmid pDC3, containing a 7-kilobase (kb) Sau3A insert, restores dCMP deaminase activity to dcd1 mutants and leads to an average 17.5-fold overproduction of the enzyme in wild-type cells. The complementing activity of the plasmid was localized to a 4.2-kb PvuII restriction fragment within the Sau3A insert. Subcloning experiments demonstrated that a single HindIII restriction site within this fragment lies within the DCD1 gene. Subsequent DNA sequence analysis revealed a 936-nucleotide open reading frame encompassing this HindIII site. Disruption of the open reading frame by integrative transformation led to a loss of enzyme activity and confirmed that this region constitutes the dCMP deaminase gene. Northern analysis indicated that the DCD1 mRNA is a 1.15-kb poly(A)+ transcript. The 5' end of the transcript was mapped by primer extension and appears to exhibit heterogeneous termini. Comparison of the amino acid sequence of the T2 bacteriophage dCMP deaminase with that deduced for the yeast enzyme revealed a limited degree of homology which extends over the entire length of the phage polypeptide (188 amino acids) but is confined to the carboxy-terminal half of the yeast protein (312 amino acids). A potential dTTP-binding site in the yeast and phage enzymes was identified by comparison of homologous regions with the amino acid sequences of a variety of other dTTP-binding enzymes. Despite the role of dCMP deaminase in dTTP biosynthesis, Northern analysis revealed that the DCD1 gene is not subject to the same cell cycle-dependent pattern of transcription recently found for the yeast thymidylate synthetase gene (TMP1).


2004 ◽  
Vol 70 (3) ◽  
pp. 1570-1575 ◽  
Author(s):  
Dae Heoun Baek ◽  
Jae Jun Song ◽  
Seok-Joon Kwon ◽  
Chung Park ◽  
Chang-Min Jung ◽  
...  

ABSTRACT A new thermostable dipeptidase gene was cloned from the thermophile Brevibacillus borstelensis BCS-1 by genetic complementation of the d-Glu auxotroph Escherichia coli WM335 on a plate containing d-Ala-d-Glu. Nucleotide sequence analysis revealed that the gene included an open reading frame coding for a 307-amino-acid sequence with an M r of 35,000. The deduced amino acid sequence of the dipeptidase exhibited 52% similarity with the dipeptidase from Listeria monocytogenes. The enzyme was purified to homogeneity from recombinant E. coli WM335 harboring the dipeptidase gene from B. borstelensis BCS-1. Investigation of the enantioselectivity (E) to the P1 and P1′ site of Ala-Ala revealed that the ratio of the specificity constant (k cat /Km ) for l-enantioselectivity to the P1 site of Ala-Ala was 23.4 � 2.2 [E = (k cat /Km ) l,d /(k cat /Km ) d,d ], while the d-enantioselectivity to the P1′ site of Ala-Ala was 16.4 � 0.5 [E = (k cat /Km ) l,d /(k cat /Km ) l,l ] at 55�C. The enzyme was stable up to 55�C, and the optimal pH and temperature were 8.5 and 65�C, respectively. The enzyme was able to hydrolyze l-Asp-d-Ala, l-Asp-d-AlaOMe, Z-d-Ala-d-AlaOBzl, and Z-l-Asp-d-AlaOBzl, yet it could not hydrolyze d-Ala-l-Asp, d-Ala-l-Ala, d-AlaNH2, and l-AlaNH2. The enzyme also exhibited β-lactamase activity similar to that of a human renal dipeptidase. The dipeptidase successfully synthesized the precursor of the dipeptide sweetener Z-l-Asp-d-AlaOBzl.


Genetics ◽  
1987 ◽  
Vol 116 (1) ◽  
pp. 67-73
Author(s):  
Tim P Keith ◽  
Margaret A Riley ◽  
Martin Kreitman ◽  
R C Lewontin ◽  
Daniel Curtis ◽  
...  

ABSTRACT We determined the nucleotide sequence of a 4.6-kb Eco RI fragment containing 70% of the rosy locus. In combination with information on the 5′ sequence, the gene has been sequenced in entirety. rosy cDNAs have been isolated and intron/exon boundaries have been determined. We find an open reading frame which spans four exons and would encode a protein of 1335 amino acids. The molecular weight of the encoded protein (xanthine dehydrogenase), based on the amino acid translation, is 146,898 daltons which agrees well with earlier biophysical estimates. Characteristics of the protein are discussed.


Genetics ◽  
1992 ◽  
Vol 131 (3) ◽  
pp. 531-539 ◽  
Author(s):  
C Bornaes ◽  
J G Petersen ◽  
S Holmberg

Abstract The catabolic L-serine (L-threonine) dehydratase of Saccharomyces cerevisiae allows the yeast to grow on media with L-serine or L-threonine as sole nitrogen source. Previously we have cloned the CHA1 gene by complementation of a mutant, cha1, lacking the dehydratase activity. Here we present the DNA sequence of a 1,766-bp fragment of the CHA1 region encompassing an open reading frame of 1080 bp. Comparison of the predicted amino acid sequence of the CHA1 polypeptide with that of other serine/threonine dehydratases revealed several blocks of sequence homology. Thus, the amino acid sequence of rat liver serine dehydratase (SDH2) and the CHA1 polypeptide are 44% homologous allowing for conservative substitutions, while 36% similarity is found between the catabolic threonine dehydratase (tdcB) of Escherichia coli and the CHA1 protein. This strongly suggests that CHA1 is the structural gene for the yeast catabolic serine (threonine) dehydratase. S1-nuclease mapping of the CHA1 mRNA ends showed a major transcription initiation site corresponding to an untranslated leader of about 19 nucleotides, while a major polyadenylation site was located about 86 nucleotides downstream from the open reading frame. Furthermore, we have mapped the chromosomal position of the CHA1 gene to less than 0.5 kb centromere proximal to HML on the left arm of chromosome III.


1999 ◽  
Vol 67 (6) ◽  
pp. 3168-3170 ◽  
Author(s):  
Caroline E. Cameron ◽  
Christa Castro ◽  
Sheila A. Lukehart ◽  
Wesley C. Van Voorhis

ABSTRACT Previous investigations have demonstrated that immunization withTreponema pallidum subsp. pallidumglycerophosphodiester phosphodiesterase significantly protects rabbits from subsequent treponeme challenge. In this report, we show that the glycerophosphodiester phosphodiesterase amino acid sequence is conserved among 12 strains from a total of five pathogenic treponemes. The invariant nature of this immunoprotective antigen makes it an attractive candidate for inclusion in a universal subunit vaccine against T. pallidum infection. In addition, these studies show a silent nucleotide substitution at position 579 of thegpd open reading frame which is consistently observed in the non-T. pallidum subsp. pallidum strains. This sequence alteration introduces a PleI restriction site in the nonsyphilis strains and thus allows genetic differentiation fromT. pallidum subsp. pallidum strains.


1999 ◽  
Vol 181 (22) ◽  
pp. 6977-6986 ◽  
Author(s):  
Susanne Wilhelm ◽  
Jan Tommassen ◽  
Karl-Erich Jaeger

ABSTRACT A lipase-negative deletion mutant of Pseudomonas aeruginosa PAO1 still showed extracellular lipolytic activity toward short-chain p-nitrophenylesters. By screening a genomic DNA library of P. aeruginosa PAO1, an esterase gene, estA, was identified, cloned, and sequenced, revealing an open reading frame of 1,941 bp. The product ofestA is a 69.5-kDa protein, which is probably processed by removal of an N-terminal signal peptide to yield a 67-kDa mature protein. A molecular mass of 66 kDa was determined for35S-labeled EstA by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. The amino acid sequence of EstA indicated that the esterase is a member of a novel GDSL family of lipolytic enzymes. The estA gene showed high similarity to an open reading frame of unknown function located in thetrpE-trpG region of P. putida and to a gene encoding an outer membrane esterase of Salmonella typhimurium. Amino acid sequence alignments led us to predict that this esterase is an autotransporter protein which possesses a carboxy-terminal β-barrel domain, allowing the secretion of the amino-terminal passenger domain harboring the catalytic activity. Expression of estA in P. aeruginosa andEscherichia coli and subsequent cell fractionation revealed that the enzyme was associated with the cellular membranes. Trypsin treatment of whole cells released a significant amount of esterase, indicating that the enzyme was located in the outer membrane with the catalytic domain exposed to the surface. To our knowledge, this esterase is unique in that it exemplifies in P. aeruginosa(i) the first enzyme identified in the outer membrane and (ii) the first example of a type IV secretion mechanism.


2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Karol Stasiak ◽  
Magdalena Dunowska ◽  
Jerzy Rola

Abstract Background Equid herpesvirus 1 (EHV-1) infections are endemic worldwide, including Poland. Many are subclinical, but some are associated with respiratory disease, abortion, neonatal foal death, or neurological disease. We describe an outbreak of abortions in Arabian mares at a well-managed State stud farm in Poland. Case presentation Eight of 30 pregnant mares aborted and one gave birth to a weak foal that died within 72 h after birth. EHV-1 was isolated from all fetuses as well as from the diseased foal. All viruses belonged to the N752 variant based on the predicted open reading frame (ORF) 30 amino acid sequence. All were identical to each other and to previous EHV-1 viruses from the same stud based on the ORF68 sequence analysis. The outbreak coincided with the lapse in the routine yearly EHV-1/4 vaccinations of the mares. Conclusions Multiple abortion due to EHV-1 infection can occur in well-managed groups of horses. Reactivation of latent EHV-1 in one of the resident mares followed by a horizontal spread was considered the most likely explanation for the outbreak. Routine vaccination is an important part of a herd-heath program.


1986 ◽  
Vol 6 (5) ◽  
pp. 1711-1721 ◽  
Author(s):  
E M McIntosh ◽  
R H Haynes

The dCMP deaminase gene (DCD1) of Saccharomyces cerevisiae has been isolated by screening a Sau3A clone bank for complementation of the dUMP auxotrophy exhibited by dcd1 dmp1 haploids. Plasmid pDC3, containing a 7-kilobase (kb) Sau3A insert, restores dCMP deaminase activity to dcd1 mutants and leads to an average 17.5-fold overproduction of the enzyme in wild-type cells. The complementing activity of the plasmid was localized to a 4.2-kb PvuII restriction fragment within the Sau3A insert. Subcloning experiments demonstrated that a single HindIII restriction site within this fragment lies within the DCD1 gene. Subsequent DNA sequence analysis revealed a 936-nucleotide open reading frame encompassing this HindIII site. Disruption of the open reading frame by integrative transformation led to a loss of enzyme activity and confirmed that this region constitutes the dCMP deaminase gene. Northern analysis indicated that the DCD1 mRNA is a 1.15-kb poly(A)+ transcript. The 5' end of the transcript was mapped by primer extension and appears to exhibit heterogeneous termini. Comparison of the amino acid sequence of the T2 bacteriophage dCMP deaminase with that deduced for the yeast enzyme revealed a limited degree of homology which extends over the entire length of the phage polypeptide (188 amino acids) but is confined to the carboxy-terminal half of the yeast protein (312 amino acids). A potential dTTP-binding site in the yeast and phage enzymes was identified by comparison of homologous regions with the amino acid sequences of a variety of other dTTP-binding enzymes. Despite the role of dCMP deaminase in dTTP biosynthesis, Northern analysis revealed that the DCD1 gene is not subject to the same cell cycle-dependent pattern of transcription recently found for the yeast thymidylate synthetase gene (TMP1).


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