scholarly journals Characterization of the Genes Encoding d-Amino Acid Transaminase and Glutamate Racemase, Two d-Glutamate Biosynthetic Enzymes of Bacillus sphaericus ATCC 10208

1998 ◽  
Vol 180 (16) ◽  
pp. 4319-4323 ◽  
Author(s):  
Ian G. Fotheringham ◽  
Stefan A. Bledig ◽  
Paul P. Taylor
Keyword(s):  
Cell Wall ◽  
Amino Acid ◽  
Sequence Homology ◽  
Bacillus Sphaericus ◽  
Primary Sequence ◽  
Gene Encoding ◽  
Sequence Identity ◽  
Glutamate Racemase ◽  
Genes Encoding

ABSTRACT In Bacillus sphaericus and other Bacillusspp., d-amino acid transaminase has been considered solely responsible for biosynthesis of d-glutamate, an essential component of cell wall peptidoglycan, in contrast to the glutamate racemase employed by many other bacteria. We report here the cloning of the dat gene encoding d-amino acid transaminase and the glr gene encoding a glutamate racemase from B. sphaericus ATCC 10208. The glrgene encodes a 28.8-kDa protein with 40 to 50% sequence identity to the glutamate racemases of Lactobacillus,Pediococcus, and Staphylococcus species. Thedat gene encodes a 31.4-kDa peptide with 67% primary sequence homology to the d-amino acid transaminase of the thermophilic Bacillus sp. strain YM1.

scholarly journals Two Alternative Pathways for the Synthesis of the Rare Compatible Solute Mannosylglucosylglycerate in Petrotoga mobilis

2010 ◽  
Vol 192 (6) ◽  
pp. 1624-1633 ◽  
Author(s):  
Chantal Fernandes ◽  
Vitor Mendes ◽  
Joana Costa ◽  
Nuno Empadinhas ◽  
Carla Jorge ◽  
...  
Keyword(s):  
Sequence Homology ◽  
Thermotoga Maritima ◽  
Functional Characterization ◽  
Compatible Solute ◽  
Homologous Gene ◽  
Gene Encoding ◽  
Alternative Pathways ◽  
Cell Extracts ◽  
Genes Encoding

ABSTRACT The compatible solute mannosylglucosylglycerate (MGG), recently identified in Petrotoga miotherma, also accumulates in Petrotoga mobilis in response to hyperosmotic conditions and supraoptimal growth temperatures. Two functionally connected genes encoding a glucosyl-3-phosphoglycerate synthase (GpgS) and an unknown glycosyltransferase (gene Pmob_1143), which we functionally characterized as a mannosylglucosyl-3-phosphoglycerate synthase and designated MggA, were identified in the genome of Ptg. mobilis. This enzyme used the product of GpgS, glucosyl-3-phosphoglycerate (GPG), as well as GDP-mannose to produce mannosylglucosyl-3-phosphoglycerate (MGPG), the phosphorylated precursor of MGG. The MGPG dephosphorylation was determined in cell extracts, and the native enzyme was partially purified and characterized. Surprisingly, a gene encoding a putative glucosylglycerate synthase (Ggs) was also identified in the genome of Ptg. mobilis, and an active Ggs capable of producing glucosylglycerate (GG) from ADP-glucose and d-glycerate was detected in cell extracts and the recombinant enzyme was characterized, as well. Since GG has never been identified in this organism nor was it a substrate for the MggA, we anticipated the existence of a nonphosphorylating pathway for MGG synthesis. We putatively identified the corresponding gene, whose product had some sequence homology with MggA, but it was not possible to recombinantly express a functional enzyme from Ptg. mobilis, which we named mannosylglucosylglycerate synthase (MggS). In turn, a homologous gene from Thermotoga maritima was successfully expressed, and the synthesis of MGG was confirmed from GDP-mannose and GG. Based on the measurements of the relevant enzyme activities in cell extracts and on the functional characterization of the key enzymes, we propose two alternative pathways for the synthesis of the rare compatible solute MGG in Ptg. mobilis.

scholarly journals Molecular and Genetic Characterization of Propionicin F, a Bacteriocin from Propionibacterium freudenreichii

2004 ◽  
Vol 70 (12) ◽  
pp. 7303-7310 ◽  
Author(s):  
Dag Anders Brede ◽  
Therese Faye ◽  
Ola Johnsborg ◽  
Inger Ødegård ◽  
Ingolf F. Nes ◽  
...  
Keyword(s):  
Amino Acid ◽  
Structural Gene ◽  
Propionibacterium Freudenreichii ◽  
Gene Encoding ◽  
Reading Frame ◽  
Amino Acid Peptide ◽  
Close Proximity ◽  
Genes Encoding

ABSTRACT This work describes the purification and characterization of propionicin F, the first bacteriocin isolated from Propionibacterium freudenreichii. The bacteriocin has a bactericidal activity and is only active against strains of P. freudenreichii. Propionicin F appears to be formed through a processing pathway new to bacteriocins. The mass of the purified bacteriocin was determined by mass spectrometry, and the N-terminal amino acid sequence was determined by Edman degradation. Sequencing of pcfA, the bacteriocin structural gene, revealed that propionicin F corresponds to a 43-amino-acid peptide in the central part of a 255-amino-acid open reading frame, suggesting that mature propionicin F is excised from the probacteriocin by N- and C-terminal proteolytic modifications. DNA sequencing and Northern blot hybridizations revealed that pcfA is cotranscribed with genes encoding a putative proline peptidase and a protein from the radical S-adenosylmethionine family. A gene encoding an ABC transporter was also identified in close proximity to the bacteriocin structural gene. The potential role of these genes in propionicin F maturation and secretion is discussed.

scholarly journals Molecular Cloning and Characterization of Bifidobacterium bifidum 1,2-α-l-Fucosidase (AfcA), a Novel Inverting Glycosidase (Glycoside Hydrolase Family 95)

2004 ◽  
Vol 186 (15) ◽  
pp. 4885-4893 ◽  
Author(s):  
Takane Katayama ◽  
Akiko Sakuma ◽  
Takatoshi Kimura ◽  
Yutaka Makimura ◽  
Jun Hiratake ◽  
...  
Keyword(s):  
Amino Acid ◽  
Genomic Library ◽  
Bifidobacterium Bifidum ◽  
Glycoside Hydrolases ◽  
Glycoside Hydrolase Family ◽  
Amino Acid Residues ◽  
Gene Encoding ◽  
Sugar Chain ◽  
Hydrolysis Of

ABSTRACT A genomic library of Bifidobacterium bifidum constructed in Escherichia coli was screened for the ability to hydrolyze the α-(1→2) linkage of 2′-fucosyllactose, and a gene encoding 1,2-α-l-fucosidase (AfcA) was isolated. The afcA gene was found to comprise 1,959 amino acid residues with a predicted molecular mass of 205 kDa and containing a signal peptide and a membrane anchor at the N and C termini, respectively. A domain responsible for fucosidase activity (the Fuc domain; amino acid residues 577 to 1474) was localized by deletion analysis and then purified as a hexahistidine-tagged protein. The recombinant Fuc domain specifically hydrolyzed the terminal α-(1→2)-fucosidic linkages of various oligosaccharides and a sugar chain of a glycoprotein. The stereochemical course of the hydrolysis of 2′-fucosyllactose was determined to be inversion by using 1H nuclear magnetic resonance. The primary structure of the Fuc domain exhibited no similarity to those of any glycoside hydrolases (GHs) but showed high similarity to those of several hypothetical proteins in a database. Thus, it was revealed that the AfcA protein constitutes a novel inverting GH family (GH family 95).

Biochemical characterization of a glucoamylase from Saccharomycopsis fibuligera R64

Biologia ◽  
2011 ◽  
Vol 66 (1) ◽  
Author(s):  
Dessy Natalia ◽  
Keni Vidilaseris ◽  
Pasjan Satrimafitrah ◽  
Wangsa Ismaya ◽  
Purkan ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Amino Acid ◽  
Amino Acid Sequence Identity ◽  
Biochemical Characterization ◽  
Saccharomycopsis Fibuligera ◽  
Sequence Identity ◽  
Ic50 Value ◽  
High Amino Acid ◽  
Ph Range

AbstractGlucoamylase from the yeast Saccharomycopsis fibuligera R64 (GLL1) has successfully been purified and characterized. The molecular mass of the enzyme was 56,583 Da as determined by mass spectrometry. The purified enzyme demonstrated optimum activity in the pH range of 5.6–6.4 and at 50°C. The activity of the enzyme was inhibited by acarbose with the IC50 value of 5 μM. GLL1 shares high amino acid sequence identity with GLU1 and GLA1, which are Saccharomycopsis fibuligera glucoamylases from the strains HUT7212 and KZ, respectively. The properties of GLL1, however, resemble that of GLU1. The elucidation of the primary structure of GLL1 contributes to the explanation of this finding.

scholarly journals Identification of Streptococci to Species Level by Sequencing the Gene Encoding the Manganese-Dependent Superoxide Dismutase

1998 ◽  
Vol 36 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Claire Poyart ◽  
Gilles Quesne ◽  
Stephane Coulon ◽  
Patrick Berche ◽  
Patrick Trieu-Cuot
Keyword(s):  
Superoxide Dismutase ◽  
Pcr Assay ◽  
Degenerate Primers ◽  
Gene Encoding ◽  
Genes Encoding ◽  
Type Strains ◽  
Internal Fragment ◽  
Rrna Sequences ◽  
16S Rrna Sequences

We have used a PCR assay based on the use of degenerate primers in order to characterize an internal fragment (sodAint ) representing approximately 85% of the genes encoding the manganese-dependent superoxide dismutase in various streptococcal type strains (S. acidominimus,S. agalactiae, S. alactolyticus, S. anginosus, S. bovis, S. constellatus,S. canis, S. cricetus, S. downei,S. dysgalactiae, S. equi subsp.equi, S. equi subsp. zooepidemicus,S. equinus, S. gordonii, S. iniae,S. intermedius, S. mitis, S. mutans, S. oralis, S. parasanguis,S. pneumoniae, S. porcinus, S. pyogenes, S. salivarius, S. sanguis,S. sobrinus, S. suis, S. thermophilus, and S. vestibularis). Phylogenetic analysis of these sodAint fragments yields an evolutionary tree having a topology similar to that of the tree constructed with the 16S rRNA sequences. We have shown that clinical isolates could be identified by determining the positions of theirsodAint fragments on the phylogenetic tree of the sodAint fragments of the type species. We propose this method for the characterization of strains that cannot be assigned to a species on the basis of their conventional phenotypic reactions.

scholarly journals Nucleotide Sequence and Characterization of a Novel Cefotaxime-Hydrolyzing β-Lactamase (CTX-M-10) Isolated in Spain

2001 ◽  
Vol 45 (2) ◽  
pp. 616-620 ◽  
Author(s):  
Antonio Oliver ◽  
José Claudio Pérez-Dı́az ◽  
Teresa M. Coque ◽  
Fernando Baquero ◽  
Rafael Cantón
Keyword(s):  
Amino Acid ◽  
Nucleotide Sequence ◽  
Amino Acid Sequence Identity ◽  
Penicillin G ◽  
Nucleotide Substitutions ◽  
Sequence Identity ◽  
M 10 ◽  
Hydrolysis Rates ◽  
Kluyvera Ascorbata

ABSTRACT A cefotaxime-resistant, ceftazidime-susceptible Escherichia coli isolate was obtained from a patient with sepsis in 1997, from which a β-lactamase with a pI of 8.1 was cloned. Cephaloridine and cefotaxime relative hydrolysis rates were 167 and 81, respectively (penicillin G rate = 100), whereas ceftazidime hydrolysis was not detected. The nucleotide sequence revealed a bla gene related to that coding for CTX-M-3. Despite 21 nucleotide substitutions, only 2 determined amino acid changes (Ala27Val and Arg38Gln). The amino acid sequence identity between this enzyme, designated CTX-M-10, and the chromosomal β-lactamase ofKluyvera ascorbata was 81%.

Identification and preliminary characterization of cell-wall-anchored proteins of Staphylococcus epidermidis

Microbiology ◽  
2005 ◽  
Vol 151 (5) ◽  
pp. 1453-1464 ◽  
Author(s):  
M. Gabriela Bowden ◽  
Wei Chen ◽  
Jenny Singvall ◽  
Yi Xu ◽  
Sharon J. Peacock ◽  
...  
Keyword(s):  
Cell Wall ◽  
Staphylococcus Epidermidis ◽  
Tertiary Structure ◽  
Genomic Sequence ◽  
Human Infection ◽  
Pcr Analysis ◽  
Genes Encoding ◽  
Antibody Titres

Staphylococcus epidermidis is a ubiquitous human skin commensal that has emerged as a major cause of foreign-body infections. Eleven genes encoding putative cell-wall-anchored proteins were identified by computer analysis of the publicly available S. epidermidis unfinished genomic sequence. Four genes encode previously described proteins (Aap, Bhp, SdrF and SdrG), while the remaining seven have not been characterized. Analysis of primary sequences of the Staphylococcus epidermidis surface (Ses) proteins indicates that they have a structural organization similar to the previously described cell-wall-anchored proteins from S. aureus and other Gram-positive cocci. However, not all of the Ses proteins are direct homologues of the S. aureus proteins. Secondary and tertiary structure predictions suggest that most of the Ses proteins are composed of several contiguous subdomains, and that the majority of these predicted subdomains are folded into β-rich structures. PCR analysis indicates that certain genes may be found more frequently in disease isolates compared to strains isolated from healthy skin. Patients recovering from S. epidermidis infections had higher antibody titres against some Ses proteins, implying that these proteins are expressed during human infection. Western blot analyses of early-logarithmic and late-stationary in vitro cultures suggest that different regulatory mechanisms control the expression of the Ses proteins.

scholarly journals The Blue Copper-Containing Nitrite Reductase fromAlcaligenes xylosoxidans: Cloning of the nirAGene and Characterization of the Recombinant Enzyme

1999 ◽  
Vol 181 (8) ◽  
pp. 2323-2329 ◽  
Author(s):  
Miguel Prudêncio ◽  
Robert R. Eady ◽  
Gary Sawers
Keyword(s):  
Amino Acid ◽  
Nitrite Reductase ◽  
Recombinant Enzyme ◽  
Leader Peptide ◽  
Resonance Spectroscopy ◽  
Gene Encoding ◽  
Blue Copper

ABSTRACT The nirA gene encoding the blue dissimilatory nitrite reductase from Alcaligenes xylosoxidans has been cloned and sequenced. To our knowledge, this is the first report of the characterization of a gene encoding a blue copper-containing nitrite reductase. The deduced amino acid sequence exhibits a high degree of similarity to other copper-containing nitrite reductases from various bacterial sources. The full-length protein included a 24-amino-acid leader peptide. The nirA gene was overexpressed inEscherichia coli and was shown to be exported to the periplasm. Purification was achieved in a single step, and analysis of the recombinant Nir enzyme revealed that cleavage of the signal peptide occurred at a position identical to that for the native enzyme isolated from A. xylosoxidans. The recombinant Nir isolated directly was blue and trimeric and, on the basis of electron paramagnetic resonance spectroscopy and metal analysis, possessed only type 1 copper centers. This type 2-depleted enzyme preparation also had a low nitrite reductase enzyme activity. Incubation of the periplasmic fraction with copper sulfate prior to purification resulted in the isolation of an enzyme with a full complement of type 1 and type 2 copper centers and a high specific activity. The kinetic properties of the recombinant enzyme were indistinguishable from those of the native nitrite reductase isolated from A. xylosoxidans. This rapid isolation procedure will greatly facilitate genetic and biochemical characterization of both wild-type and mutant derivatives of this protein.

MUTANT AND CHIMAERIC RECOMBINANT PLASMINOGEN ACTIVATORS

1987 ◽  
Author(s):  
L Piérard ◽  
P Jacobs ◽  
D Gheysen ◽  
M Hoylaerts ◽  
A Cravador ◽  
...  
Keyword(s):  
Amino Acid ◽  
Plasminogen Activators ◽  
Tissue Type ◽  
Single Chain ◽  
Type Plasminogen Activator ◽  
Genes Encoding ◽  
A Chain ◽  
Mutant Forms ◽  
Kringle 2

In order to produce plasminogen activators (PA) more specific and more active than their natural counterparts, we designed recombinant genes encoding mutant forms of urokinase (u-PA) and chimaeric molecules combining fragments of tissue type plasminogen activator (t-PA) and of u-PA. The following constructs have been realized : 1°) u-PA where amino acids Arg156 and Lys158 have been replaced by Thr. The purpose of this approach was to obtain a prourokinase molecule displaying similar properties as the natural single chain urokinase (scu-PA) but resistant to the cleavage by plasmin ; 2°) u-PA where the second cleavage site, Lys135-Lys136, was also eliminated either by replacing amino acid 132 to amino acid 147 by a shorter link (Ser-Thr) as found in t-PA, or by replacing the two lysines by glutamine residues. The resulting molecules correspond thus to completely uncleavable scu-PA forms ; 3°) an hybrid composed of the finger domain of t-PA and of the B-chain of u-PA ; 4°) an hybrid made of the A-chain of t-PA and of the B-chain of u-PA ; 5°) an hybrid where the kringle 2 of t-PA has been inserted between the kringle domain and the B-chain of u-PA. The last three constructs have been made to confer the fibrin binding specificity of t-PA to the B-chain of u-PA.All recombinant DNAs were introduced, via an expression vector, into R1610 and CosI cells. Secretion of the recombinant products was monitored by ELISA and activities were assayed in an immobilized system involving a monoclonal antibody (AAU2) raised against 33K u-PA, plasminogen and the specific chromogenic substrate S2251. In this assay, all recombinant products, except the plasmin resistant (156-158) scu-PA, showed apparent specific activities comparable to the activity of natural two-chain u-PA. Potential interest of these new plasminogen activators in therapy will be discussed and further characterization of the new molecules will-be presented.

scholarly journals Identification and Characterization of a Porcine Torovirus

1998 ◽  
Vol 72 (5) ◽  
pp. 3507-3511 ◽  
Author(s):  
A. Kroneman ◽  
L. A. H. M. Cornelissen ◽  
M. C. Horzinek ◽  
R. J. de Groot ◽  
H. F. Egberink
Keyword(s):  
Longitudinal Study ◽  
Neutralizing Antibodies ◽  
Rt Pcr ◽  
Gene Encoding ◽  
Nucleocapsid Gene ◽  
Sequence Identity ◽  
Young Pigs ◽  
Porcine Torovirus ◽  
Identification And Characterization

ABSTRACT A porcine torovirus (PoTV) was identified and characterized; it is a novel member of the genus Torovirus (familyCoronaviridae, order Nidovirales), closely related to but clearly distinct from the already recognized equine torovirus (ETV) and bovine torovirus (BoTV) representatives. Immunoelectron microscopy of feces from piglets revealed elongated, 120- by 55-nm particles which were recognized by a torovirus-specific antiserum. Amplification by reverse transcriptase (RT) PCR with primers designed to detect conserved regions (on the basis of the genomes of BoTV strain Breda and ETV strain Berne) resulted in the identification of the 489-bp nucleocapsid gene, encoding a 18.7-kDa protein. The sequence identity in this region between PoTV and both ETV and BoTV was only about 68%, whereas the latter two show 81% identity. Neutralizing antibodies directed against ETV were found in sera of adult and young pigs. In all 10 herds sampled, seropositive animals were present, and 81% of randomly selected adult sows possessed antibodies. A longitudinal study with RT PCR showed that piglets shed virus in the feces for 1 or more days, starting 4 to 14 days after weaning.

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