scholarly journals Characterization of a Eukaryotic-Like Tyrosine Protein Kinase Expressed by the Shiga Toxin-Encoding Bacteriophage 933W

2004 ◽  
Vol 186 (11) ◽  
pp. 3472-3479 ◽  
Author(s):  
Jessica S. Tyler ◽  
David I. Friedman
Keyword(s):  
Shiga Toxin ◽  
Pathogenic Bacteria ◽  
Kinase Activity ◽  
Catalytic Domain ◽  
Selective Pressure ◽  
Sequence Similarity ◽  
Amino Acid Sequence Similarity ◽  
Reading Frame ◽  
Tyrosine Protein Kinase

ABSTRACT The Shiga toxin (Stx)-encoding bacteriophage 933W contains an open reading frame, stk, with amino acid sequence similarity to the catalytic domain of eukaryotic serine/threonine (Ser/Thr) protein kinases (PKs). Eukaryotic PKs are related by a common catalytic domain, consisting of invariant and nearly invariant residues necessary for ATP binding and phosphotransfer. We demonstrate that rather than a Ser/Thr kinase, stk encodes a eukaryotic-like tyrosine (Tyr) kinase. An affinity-purified recombinant Stk (rStk) autophosphorylates and catalyzes the phosphorylation of an artificial substrate on Tyr residues and not on Ser or Thr residues. A change of an invariant lysine within the putative catalytic domain abolishes this kinase activity, indicating that Stk uses a phosphotransfer mechanism similar to the mechanism used by eukaryotic PKs. We provide evidence suggesting that stk is cotranscribed with cI from the phage promoter responsible for maintaining CI expression during lysogeny. The stk gene was identified in prophages obtained from independently isolated Stx-producing Escherichia coli clinical isolates, suggesting that selective pressure has maintained the stk gene in these pathogenic bacteria.

scholarly journals Biochemical and Genetic Characterization of Propionicin T1, a New Bacteriocin from Propionibacterium thoenii

2000 ◽  
Vol 66 (10) ◽  
pp. 4230-4236 ◽  
Author(s):  
Therese Faye ◽  
Thor Langsrud ◽  
Ingolf F. Nes ◽  
Helge Holo
Keyword(s):  
Amino Acids ◽  
Stop Codon ◽  
Sequence Similarity ◽  
Propionibacterium Freudenreichii ◽  
Terminal Part ◽  
Reading Frame ◽  
Lactobacillus Sake ◽  
Propionibacterium Thoenii ◽  
Self Protection

ABSTRACT A collection of propionibacteria was screened for bacteriocin production. A new bacteriocin named propionicin T1 was isolated from two strains of Propionibacterium thoenii. This bacteriocin shows no sequence similarity to other bacteriocins. Propionicin T1 was active against all strains of Propionibacterium acidipropionici, Propionibacterium thoenii, andPropionibacterium jensenii tested and also againstLactobacillus sake NCDO 2714 but showed no activity againstPropionibacterium freudenreichii. The bacteriocin was purified, and the N-terminal part of the peptide was determined with amino acid sequencing. The corresponding gene pctA was sequenced, and this revealed that propionicin T1 is produced as a prebacteriocin of 96 amino acids with a typical sec leader, which is processed to give a mature bacteriocin of 65 amino acids. An open reading frame encoding a protein of 424 amino acids was found 68 nucleotides downstream the stop codon of pctA. The N-terminal part of this putative protein shows strong similarity with the ATP-binding cassette of prokaryotic and eukaryotic ABC transporters, and this protein may be involved in self-protection against propionicin T1. Propionicin T1 is the first bacteriocin from propionibacteria that has been isolated and further characterized at the molecular level.

scholarly journals Programmed Translational Frameshift in the Bacteriophage P2 FETUD Tail Gene Operon

2002 ◽  
Vol 184 (23) ◽  
pp. 6522-6531 ◽  
Author(s):  
Gail E. Christie ◽  
Louise M. Temple ◽  
Becky A. Bartlett ◽  
Tina S. Goodwin
Keyword(s):  
Gene Cluster ◽  
Sequence Similarity ◽  
Initiation Site ◽  
Translation Initiation Site ◽  
Amino Acid Sequence Similarity ◽  
Reading Frame ◽  
Coding Regions ◽  
Translational Frameshift ◽  
Bacteriophage P2 ◽  
Contractile Tail

ABSTRACT The major structural components of the P2 contractile tail are encoded in the FETUD tail gene operon. The sequences of genes F I and F II, encoding the major tail sheath and tail tube proteins, have been reported previously (L. M. Temple, S. L. Forsburg, R. Calendar, and G. E. Christie, Virology 181:353-358, 1991). Sequence analysis of the remainder of this operon and the locations of amber mutations Eam30, Tam5, Tam64, Tam215, Uam25, Uam77, Uam92, and Dam6 and missense mutation Ets55 identified the coding regions for genes E, T, U, and D, completing the sequence determination of the P2 genome. Inspection of the DNA sequence revealed a new open reading frame overlapping the end of the essential tail gene E. Lack of an apparent translation initiation site and identification of a putative sequence for a programmed translational frameshift within the E gene suggested that this new reading frame (E′) might be translated as an extension of gene E, following a −1 translational frameshift. Complementation analysis demonstrated that E′ was essential for P2 lytic growth. Analysis of fusion polypeptides verified that this reading frame was translated as a −1 frameshift extension of gpE, with a frequency of approximately 10%. The arrangement of these two genes within the tail gene cluster of phage P2 and their coupling via a translational frameshift appears to be conserved among P2-related phages. This arrangement shows a striking parallel to the organization in the tail gene cluster of phage lambda, despite a lack of amino acid sequence similarity between the tail gene products of these phage families.

scholarly journals The Glycosyltransferase Domain of Penicillin-Binding Protein 2a from Streptococcus pneumoniae Catalyzes the Polymerization of Murein Glycan Chains

2003 ◽  
Vol 185 (15) ◽  
pp. 4418-4423 ◽  
Author(s):  
Anne Marie Di Guilmi ◽  
Andréa Dessen ◽  
Otto Dideberg ◽  
Thierry Vernet
Keyword(s):  
Streptococcus Pneumoniae ◽  
Pathogenic Bacteria ◽  
Catalytic Domain ◽  
Soluble Form ◽  
Lipid Ii ◽  
Extracellular Region ◽  
Catalytically Active ◽  
Bacterial Peptidoglycan

ABSTRACT The bacterial peptidoglycan consists of glycan chains of repeating β-1,4-linked N-acetylglucosaminyl-N-acetylmuramyl units cross-linked through short peptide chains. The polymerization of the glycans, or glycosyltransfer (GT), and transpeptidation (TP) are catalyzed by bifunctional penicillin-binding proteins (PBPs). The β-lactam antibiotics inhibit the TP reaction, but their widespread use led to the development of drug resistance in pathogenic bacteria. In this context, the GT catalytic domain represents a potential target in the antibacterial fight. In this work, the in vitro polymerization of glycan chains by the extracellular region of recombinant Streptococcus pneumoniae PBP2a, namely, PBP2a* (the asterisk indicates the soluble form of the protein) is presented. Dansylated lipid II was used as the substrate, and the kinetic parameters K m and k cat/K m were measured at 40.6 μM (± 15.5) and 1 × 10−3 M−1 s−1, respectively. The GT reaction catalyzed by PBP2a* was inhibited by moenomycin and vancomycin. Furthermore, the sequence between Lys 78 and Ser 156 is required for enzymatic activity, whereas it is dispensable for lipid II binding. In addition, we confirmed that this region of the protein is also involved in membrane interaction, independently of the transmembrane anchor. The characterization of the catalytically active GT domain of S. pneumoniae PBP2a may contribute to the development of new inhibitors, which are urgently needed to renew the antibiotic arsenal.

scholarly journals Characterization of a U.S. Isolate of Beet black scorch virus

2007 ◽  
Vol 97 (10) ◽  
pp. 1245-1254 ◽  
Author(s):  
John J. Weiland ◽  
David Van Winkle ◽  
Michael C. Edwards ◽  
Rebecca L. Larson ◽  
Weilin L. Shelver ◽  
...  
Keyword(s):  
Coat Protein ◽  
Protein Gene ◽  
Sequence Similarity ◽  
Systemic Infection ◽  
Amino Acid Sequence Similarity ◽  
Adenosine Nucleotides ◽  
Tetragonia Expansa ◽  
Extension Analysis ◽  
Beet Black Scorch Virus

The first reported U.S. isolate of Beet black scorch necrovirus (BBSV) was obtained and characterized. Host range of the virus for localized and occasionally systemic infection included the Chenopodiaceae and Tetragonia expansa; Nicotiana benthamiana supported symptomless systemic infection by the virus. The complete nucleotide sequence of the genomic RNA of the virus, designated BBSV-Co, exhibits 93% similarity to the genome of the ‘Ningxia’ isolate of BBSV from China. Amino acid sequence similarity in predicted genes ranged from 95% in the p4 gene to 97% in the p82 and coat protein genes. A potential additional gene exists within the U.S. isolate of BBSV that is absent from Chinese isolates of BBSV due to nucleotide differences between these isolates within the coat protein gene. Coat protein analysis by isoelectric focusing and by mass spectroscopy indicated the presence of phosphorylated residues. Using primer extension analysis of the 5′ end of the genome and site-directed mutants of genomic clones of BBSV-Co from which infectious RNA was produced, the native 5′ end of the BBSV-Co genome was determined to be 5′-GAAACCTAACC…3′, lacking the two terminal adenosine nucleotides in the published sequences of BBSV from China.

scholarly journals Characterization of the maize Mutator transposable element MURA transposase as a DNA-binding protein.

1997 ◽  
Vol 17 (9) ◽  
pp. 5165-5175 ◽  
Author(s):  
M I Benito ◽  
V Walbot
Keyword(s):  
Dna Binding ◽  
Transposable Element ◽  
Binding Protein ◽  
Sequence Similarity ◽  
Functional Characterization ◽  
Dna Binding Protein ◽  
Amino Acid Sequence Similarity ◽  
Mobility Shift ◽  
Gel Mobility Shift

The autonomous MuDR element of the Mutator (Mu) transposable element family of maize encodes at least two proteins, MURA and MURB. Based on amino acid sequence similarity, previous studies have reported that MURA is likely to be a transposase. The functional characterization of MURA has been hindered by the instability of its cDNA, mudrA, in Escherichia coli. In this study, we report the first successful stabilization and expression of MURA in Saccharomyces cerevisiae. Gel mobility shift assays demonstrate that MURA is a DNA-binding protein that specifically binds to sequences within the highly conserved Mu element terminal inverted repeats (TIRs). DNase I and 1,10-phenanthroline-copper footprinting of MURA-Mu1 TIR complexes indicate that MURA binds to a conserved approximately 32-bp region in the TIR of Mu1. In addition, MURA can bind to the same region in the TIRs of all tested actively transposing Mu elements but binds poorly to the diverged Mu TIRs of inactive elements. Previous studies have reported a correlation between Mu transposon inactivation and methylation of the Mu element TIRs. Gel mobility shift assays demonstrate that MURA can interact differentially with unmethylated, hemimethylated, and homomethylated TIR substrates. The significance of MURA's interaction with the TIRs of Mu elements is discussed in the context of what is known about the regulation and mechanisms of Mutator activities in maize.

scholarly journals Transcriptomic Characterization of the South American Freshwater Stingray Potamotrygon motoro Venom Apparatus

Toxins ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 544 ◽  
Author(s):  
Filipe Silva ◽  
Yu Huang ◽  
Vítor Yang ◽  
Xidong Mu ◽  
Qiong Shi ◽  
...  
Keyword(s):  
Selective Pressure ◽  
Sequence Similarity ◽  
Venom Gland ◽  
High Expression ◽  
South American ◽  
The South ◽  
Freshwater Stingray ◽  
Taxonomic Range ◽  
Available Information

Venomous animals are found through a wide taxonomic range including cartilaginous fish such as the freshwater stingray Potamotrygon motoro occurring in South America, which can injure people and cause venom-related symptoms. Ensuring the efficacy of drug development to treat stingray injuries can be assisted by the knowledge of the venom composition. Here we performed a detailed transcriptomic characterization of the venom gland of the South American freshwater stingray Potamotrygon motoro. The transcripts retrieved showed 418 hits to venom components (comparably to 426 and 396 hits in other two Potamotrygon species), with high expression levels of hyaluronidase, cystatin and calglandulin along with hits uniquely found in P. motoro such as DELTA-alicitoxin-Pse1b, Augerpeptide hhe53 and PI-actitoxin-Aeq3a. We also identified undescribed molecules with extremely high expression values with sequence similarity to the SE-cephalotoxin and Rapunzel genes. Comparative analyses showed that despite being closely related, there may be significant variation among the venoms of freshwater stingrays, highlighting the importance of considering elicit care in handling different envenomation cases. Since hyaluronidase represents a major component of fish venom, we have performed phylogenetic and selective pressure analyses of this gene/protein across all fish with the available information. Results indicated an independent recruitment of the hyaluronidase into the stingray venom relative to that of venomous bony fish. The hyaluronidase residues were found to be mostly under negative selection, but 18 sites showed evidence of diversifying positive selection (P < 0.05). Our data provides new insight into stingray venom variation, composition, and selective pressure in hyaluronidase.

scholarly journals SpCoel1: a sea urchin profilin gene expressed specifically in coelomocytes in response to injury.

1992 ◽  
Vol 3 (4) ◽  
pp. 403-414 ◽  
Author(s):  
L C Smith ◽  
R J Britten ◽  
E H Davidson
Keyword(s):  
Sea Urchin ◽  
Sequence Similarity ◽  
Single Copy ◽  
Untranslated Regions ◽  
Amino Acid Sequence Similarity ◽  
Signal Transduction System ◽  
Reading Frame ◽  
Purple Sea Urchin ◽  
Copy Gene ◽  
External Injury

SpCoel1 is a single copy gene that is specifically expressed in most of the coelomocytes of the adult purple sea urchin, Strongylocentrotus purpuratus. The 4-kb transcript from this gene has a relatively short (426 nucleotide) open reading frame (ORF) with long 3' and 5' untranslated regions. The ORF encodes a protein that has strong amino acid sequence similarity to profilins from yeast to mammals. Transcript titrations of SpCoel1 show significant increases per coelomocyte in animals that have been physiologically challenged. Increases in transcript levels are of similar magnitudes between animals receiving different treatments, such as injuries from needle punctures or from injections of foreign cells. The evidence presented here implies a molecular mechanism by which this lower deuterostome defense system responds to external insult, viz that an external "injury signal" activates a signal transduction system, which in turn mediates the alterations in cytoskeletal state that are required for coelomocyte activation.

scholarly journals MBOVPG45_0375 Encodes an IgG-Binding Protein and MBOVPG45_0376 Encodes an IgG-Cleaving Protein in Mycoplasma bovis

2021 ◽  
Vol 8 ◽  
Author(s):  
Haoran Zhao ◽  
Yunke Zhang ◽  
Zhanhui Wang ◽  
Mengyao Liu ◽  
Pengpeng Wang ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Specific Binding ◽  
Binding Protein ◽  
Sequence Similarity ◽  
Expression System ◽  
Bacterial Pathogen ◽  
Amino Acid Sequence Similarity ◽  
Mycoplasma Bovis ◽  
Fab Fragment ◽  
Igg Binding

Mycoplasma bovis is a significant bacterial pathogen which is able to persist in cattle and cause chronic diseases. This phenomenon may relate to M. bovis evading the immune system of the host. Immunoglobulin-binding proteins are widely distributed in a variety of pathogenic bacteria, including some Mycoplasma species. These proteins are considered to help the bacteria evade the immune response of the host. Here we found M. bovis strain PG45 can bind to IgG from several animals. MBOVPG45_0375 encodes a putative membrane protein, has strong amino acid sequence similarity with Immunoglobulin G-binding protein in Mycoplasma mycoides subsp. capri. Hence, we constructed recombinant MBOVPG45_0375 (r0375) in the Escherichia coli expression system and demonstrated that r0375 can bind to IgG non-immunologically rather than specific binding similar to interaction of antigen and antibody. Moreover, r0375 can bind to the Fab fragment of IgG. Also, the binding of r0375 and IgG inhibits the formation of antigen-antibody union. Furthermore, MBOVPG45_0376 encodes an IgG-cleaving protein of M. bovis strain PG45. Nevertheless, r0375 binding to IgG is required for the cleavage activity of recombinant 0376 (r0376). The activity of r0376 is also affected by incubation time and temperature. In addition, we found both MBOVPG45_0375 and MBOVPG45_0376 are membrane proteins of M. bovis strain PG45. These results about MBOVPG45_0375 as an IgG-binding protein and MBOVPG45_0376 as an IgG-cleaving protein offer a new insight into the interaction between M. bovis and its host.

scholarly journals Characterization of novel bacteriophage phiC119 capable of lysing multidrug-resistant Shiga toxin-producingEscherichia coliO157:H7

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2423 ◽  
Author(s):  
Luis Amarillas ◽  
Cristóbal Chaidez ◽  
Arturo González-Robles ◽  
Yadira Lugo-Melchor ◽  
Josefina León-Félix
Keyword(s):  
Host Range ◽  
Shiga Toxin ◽  
Pathogenic Bacteria ◽  
Genetic Material ◽  
Multidrug Resistant ◽  
Broad Host Range ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Tract Infections

BackgroundShiga toxin-producingEscherichia coli(STEC) is one of the most common and widely distributed foodborne pathogens that has been frequently implicated in gastrointestinal and urinary tract infections. Moreover, high rates of multiple antibiotic-resistantE. colistrains have been reported worldwide. Due to the emergence of antibiotic-resistant strains, bacteriophages are considered an attractive alternative to biocontrol pathogenic bacteria. Characterization is a preliminary step towards designing a phage for biocontrol.MethodsIn this study, we describe the characterization of a bacteriophage designated phiC119, which can infect and lyse several multidrug-resistant STEC strains and someSalmonellastrains. The phage genome was screened to detect thestx-genes using PCR, morphological analysis, host range was determined, and genome sequencing were carried out, as well as an analysis of the cohesive ends and identification of the type of genetic material through enzymatic digestion of the genome.ResultsAnalysis of the bacteriophage particles by transmission electron microscopy showed that it had an icosahedral head and a long tail, characteristic of the familySiphoviridae. The phage exhibits broad host range against multidrug-resistant and highly virulentE. coliisolates. One-step growth experiments revealed that the phiC119 phage presented a large burst size (210 PFU/cell) and a latent period of 20 min. Based on genomic analysis, the phage contains a linear double-stranded DNA genome with a size of 47,319 bp. The phage encodes 75 putative proteins, but lysogeny and virulence genes were not found in the phiC119 genome.ConclusionThese results suggest that phage phiC119 may be a good biological control agent. However, further studies are required to ensure its control of STEC and to confirm the safety of phage use.

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