scholarly journals Monooxygenase-like sequence of a Rhodococcus equi gene conferring increased resistance to rifampin by inactivating this antibiotic.

1997 ◽  
Vol 41 (1) ◽  
pp. 218-221 ◽  
Author(s):  
S J Andersen ◽  
S Quan ◽  
B Gowan ◽  
E R Dabbs

A DNA clone from Rhodococcus equi conferring low-level rifampin resistance through the ability to inactivate this antibiotic via its decomposition was identified. The iri (inactivation of rifampin) gene consisted of an open reading frame of 1,437 bp encoding a 479-amino-acid sequence strongly resembling those of monooxygenases acting upon phenolic compounds or involved in polyketide antibiotic synthesis. When expressed in Escherichia coli, the gene conferred resistance to a > 50-micrograms/ml concentration of the drug.

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.


2000 ◽  
Vol 68 (5) ◽  
pp. 2720-2727 ◽  
Author(s):  
Robert A. Kingsley ◽  
Karin van Amsterdam ◽  
Naomi Kramer ◽  
Andreas J. Bäumler

ABSTRACT Little is known about factors which enable Salmonellaserotypes to circulate within populations of livestock and domestic fowl. We have identified a DNA region which is present inSalmonella serotypes commonly isolated from livestock and domestic fowl (S. enterica subspecies I) but absent from reptile-associated Salmonella serotypes (S. bongori and S. enterica subspecies II to VII). This DNA region was cloned from Salmonella serotype Typhimurium and sequence analysis revealed the presence of a 6,105-bp open reading frame, designated shdA, whose product's deduced amino acid sequence displayed homology to that of AIDA-I from diarrheagenicEscherichia coli, MisL of serotype Typhimurium, and IcsA ofShigella flexneri. The shdA gene was located adjacent to xseA at 52 min, in a 30-kb DNA region which is not present in Escherichia coli K-12. A serotype Typhimurium shdA mutant was shed with the feces in reduced numbers and for a shorter period of time compared to its isogenic parent. A possible role for the shdA gene during the expansion in host range of S. enterica subspecies I to include warm-blooded vertebrates is discussed.


2000 ◽  
Vol 182 (21) ◽  
pp. 6243-6246 ◽  
Author(s):  
Haitao Zhang ◽  
George T. Javor

ABSTRACT The open reading frame at 86.7 min on the Escherichia coli chromosome, “yigC,” complemented aubiD mutant strain, AN66, indicating that yigCis the ubiD gene. The gene product, a 497-amino-acid-residue protein, showed extensive homology to the UPF 00096 family of proteins in the Swiss-Prot database.


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.


1991 ◽  
Vol 277 (2) ◽  
pp. 469-475 ◽  
Author(s):  
R Dumas ◽  
M Lebrun ◽  
R Douce

Acetohydroxy acid reductoisomerase (AHRI), the second enzyme in the parallel isoleucine/valine-biosynthetic pathway, catalyses an unusual two-step reaction in which the substrate, either 2-acetolactate or 2-aceto-2-hydroxybutyrate, is converted via an alkyl migration and an NADPH-dependent reduction to give 2,3-dihydroxy-3-methylbutyrate or 2,3-dihydroxy-3-methylvalerate respectively. We have isolated and characterized a full-length cDNA from a lambda gt11 spinach library encoding the complete acetohydroxy acid reductoisomerase protein precursor. The 2050-nucleotide sequence contains a 1785-nucleotide open reading frame. The derived amino acid sequence indicates that the protein precursor consists of 595 amino acid residues including a presequence peptide of 72 amino acid residues. The N-terminal sequence of the first 16 amino acid residues of the purified AHRI confirms the identity of the cDNA. The derived amino acid sequence from this open reading frame shows 23% identity with the deduced amino acid sequences of the Escherichia coli and Saccharomyces cerevisiae AHRI proteins. There are two blocks of conserved amino acid residues in these three proteins. One of these is a sequence similar to the ‘fingerprint’ region of the NAD(P)H-binding site found in a large number of NAD(P)H-dependent oxidoreductases. The other, a short sequence (Lys-Xaa-Xaa-Xaa-Xaa-Xaa-Xaa-Xaa-Ser-His-Gly-Phe) containing the amino acids lysine and histidine, could well be the catalytic site of the first step of the AHRI reaction. Southern-blot analysis indicated that AHRI is encoded by a single gene per haploid genome of about 7.5 kbp containing at least four introns.


2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Alexander L. Greninger ◽  
Keith R. Jerome

We report the draft genome sequence of goose dicistrovirus assembled from the filtered feces of a Canadian goose from South Lake Union in Seattle, Washington. The 9.1-kb dicistronic RNA virus falls within the familyDicistroviridae; however, it shares <33% translated amino acid sequence within the nonstructural open reading frame (ORF) from aparavirus or cripavirus.


2005 ◽  
Vol 187 (6) ◽  
pp. 2030-2037 ◽  
Author(s):  
Tomokuni Abe ◽  
Eiji Masai ◽  
Keisuke Miyauchi ◽  
Yoshihiro Katayama ◽  
Masao Fukuda

ABSTRACT Vanillate and syringate are converted into protocatechuate (PCA) and 3-O-methylgallate (3MGA), respectively, by O-demethylases in Sphingomonas paucimobilis SYK-6. PCA is further degraded via the PCA 4,5-cleavage pathway, while 3MGA is degraded through multiple pathways in which PCA 4,5-dioxygenase (LigAB), 3MGA 3,4-dioxygenase (DesZ), and an unidentified 3MGA O-demethylase and gallate dioxygenase are participants. For this study, we isolated a 4.7-kb SmaI fragment that conferred on Escherichia coli the activity required for the conversion of vanillate to PCA. The nucleotide sequence of this fragment revealed an open reading frame of 1,413 bp (ligM), the deduced amino acid sequence of which showed 49% identity with that of the tetrahydrofolate (H4folate)-dependent syringate O-demethylase gene (desA). The metF and ligH genes, which are thought to be involved in H4folate-mediated C1 metabolism, were located just downstream of ligM. The crude LigM enzyme expressed in E. coli converted vanillate and 3MGA to PCA and gallate, respectively, with similar specific activities, and only in the presence of H4folate; however, syringate was not a substrate for LigM. The disruption of ligM led to significant growth retardation on both vanillate and syringate, indicating that ligM is involved in the catabolism of these substrates. The ability of the ligM mutant to transform vanillate was markedly decreased, and this mutant completely lost the 3MGA O-demethylase activity. A ligM desA double mutant completely lost the ability to transform vanillate, thus indicating that desA also contributes to vanillate degradation. All of these results indicate that ligM encodes vanillate/3MGA O-demethylase and plays an important role in the O demethylation of vanillate and 3MGA, respectively.


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