scholarly journals Intracellular α-Amylase ofStreptococcus mutans

1998 ◽  
Vol 180 (17) ◽  
pp. 4711-4717 ◽  
Author(s):  
Christine L. Simpson ◽  
Roy R. B. Russell
Keyword(s):  
Amino Acid ◽  
Amylase Activity ◽  
Signal Sequence ◽  
Amino Acid Identity ◽  
Reading Frame ◽  
Cell Extracts ◽  
Genes Encoding ◽  
Culture Supernatants ◽  
Produce Acid

ABSTRACT Sequencing upstream of the Streptococcus mutans gene for a CcpA gene homolog, regM, revealed an open reading frame, named amy, with homology to genes encoding α-amylases. The deduced amino acid sequence showed a strong similarity (60% amino acid identity) to the intracellular α-amylase of Streptococcus bovis and, in common with this enzyme, lacked a signal sequence. Amylase activity was found only in S. mutans cell extracts, with no activity detected in culture supernatants. Inactivation of amy by insertion of an antibiotic resistance marker confirmed that S. mutanshas a single α-amylase activity. The amylase activity was induced by maltose but not by starch, and no acid was produced from starch.S. mutans can, however, transport limit dextrins and maltooligosaccharides generated by salivary amylase, but inactivation of amy did not affect growth on these substrates or acid production. The amylase digested the glycogen-like intracellular polysaccharide (IPS) purified from S. mutans, but the amy mutant was able to digest and produce acid from IPS; thus, amylase does not appear to be essential for IPS breakdown. However, when grown on excess maltose, theamy mutant produced nearly threefold the amount of IPS produced by the parent strain. The role of Amy has not been established, but Amy appears to be important in the accumulation of IPS in S. mutans grown on maltose.

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 Sequence and structure of mtr, an amino acid transport gene of Neurospora crassa

Genome ◽  
1991 ◽  
Vol 34 (4) ◽  
pp. 644-651 ◽  
Author(s):  
Kenneth Koo ◽  
W. Dorsey Stuart
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Neurospora Crassa ◽  
Rna Binding ◽  
Signal Sequence ◽  
Average Length ◽  
Open Reading Frame ◽  
Mrna Transcript ◽  
S1 Nuclease ◽  
Reading Frame

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.

scholarly journals A50 Whole-genome sequencing of African swine fever isolates from Sardinia

2019 ◽  
Vol 5 (Supplement_1) ◽  
Author(s):  
C Torresi ◽  
F Granberg ◽  
L Bertolotti ◽  
A Oggiano ◽  
B Colitti ◽  
...  
Keyword(s):  
Amino Acid ◽  
Sequence Data ◽  
Temporal Distribution ◽  
African Swine Fever ◽  
Amino Acid Identity ◽  
Genotype I ◽  
Acid Identity ◽  
Wide Range ◽  
Intergenic Sequences ◽  
Genes Encoding

Abstract In order to assess the molecular epidemiology of African swine fever (ASF) in Sardinia, we analyzed a wide range of isolates from wild and domestic pigs over a 31-year period (1978–2009) by genotyping sequence data from the genes encoding the p54 and the p72 proteins and the CVR. On this basis, the analysis of the B602L gene revealed a minor difference, placing the Sardinian isolates into two clusters according to their temporal distribution. As an extension of this study, in order to achieve a higher level of discrimination, three further variable genome regions, namely p30, CD2v, and I73R/I329L, of a large number of isolates collected from outbreaks in the years 2002–14 have been investigated. Sequence analysis of the CD2v region revealed a temporal subdivision of the viruses into two subgroups. These data, together with those from the B602L gene analysis, demonstrated that the viruses circulating in Sardinia belong to p72/genotype I, but since 1990 have undergone minor genetic variations in respect to its ancestor, thus making it impossible to trace isolates, enabling a more accurate assessment of the origin of outbreaks, and extending knowledge of virus evolution. To solve this problem, we have sequenced and annotated the complete genome of nine ASF isolates collected in Sardinia between 1978 and 2012. This was achieved using sequence data determined by next-generation sequencing. The results showed a very high identity with range of nucleotide similarity among isolates of 99.5 per cent to 99.9 per cent. The ASF virus (ASFV) genomes were composed of terminal inverted repeats and conserved and non-conserved ORFs. Among the conserved ORFs, B385R, H339R, and O61R-p12 showed 100 per cent amino acid identity. The same was true for the hypervariable ORFs, with regard to X69R, DP96R, DP60R, EP153R, B407L, I10L, and L60L genes. The EP402R and B602L genes showed, as expected, an amino acid identity range of 98.5 per cent to 100 per cent and 91 per cent to 100 per cent, respectively. In addition, all of the isolates displayed variable intergenic sequences. As a whole, the results from our studies confirmed a remarkable genetic stability of the ASFV/p72 genotype I viruses circulating in Sardinia.

scholarly journals Enhancement of Secretion and Extracellular Stability of Staphylokinase in Bacillus subtilis bywprA Gene Disruption

2000 ◽  
Vol 66 (2) ◽  
pp. 476-480 ◽  
Author(s):  
Sang Jun Lee ◽  
Dong Min Kim ◽  
Kwang Hee Bae ◽  
Si Myung Byun ◽  
Jae Hoon Chung
Keyword(s):  
Bacillus Subtilis ◽  
Gene Disruption ◽  
Therapeutic Potential ◽  
Signal Sequence ◽  
Open Reading Frame ◽  
Expression Plasmid ◽  
Reading Frame ◽  
Extracellular Milieu ◽  
Foreign Proteins

ABSTRACT Staphylokinase (SAK), a polypeptide secreted byStaphylococcus aureus, is a plasminogen activator with a therapeutic potential in thrombosis diseases. A Bacillus subtilis strain which is multiply deficient in exoproteases was transformed by an expression plasmid carrying a promoter and a signal sequence of subtilisin fused in frame with the sak open reading frame. However, the amount of SAK secretion was marginal (45 mg/liter). In contrast, disruption of the wprA gene, which encodes a subtilisin-type protease, strongly promoted the production of SAK in the stationary phase (181 mg/liter). In addition, the extracellular stability of mature SAK was dramatically enhanced. These data indicate a significant role of the wprA gene product in degrading foreign proteins, both during secretion and in the extracellular milieu.

scholarly journals Molecular cloning and functional characterization of the mouse organic-anion-transporting polypeptide 1 (Oatp1) and mapping of the gene to chromosome X

1999 ◽  
Vol 345 (1) ◽  
pp. 115-120 ◽  
Author(s):  
Bruno HAGENBUCH ◽  
Ilse-Dore ADLER ◽  
Thomas E. SCHMID
Keyword(s):  
Amino Acid ◽  
Organic Anion ◽  
Functional Characterization ◽  
Amino Acid Identity ◽  
Xenopus Laevis Oocytes ◽  
Cdna Insert ◽  
Reading Frame ◽  
Acid Identity ◽  
Organic Anion Transporting Polypeptide ◽  
Cloned Cdna

We have cloned a murine member of the organic-anion-transporting polypeptide (Oatp) family of membrane-transport proteins from mouse liver. The cloned cDNA insert of 2783 bp with an open reading frame of 2011 bp codes for a 12-transmembrane 670-amino-acid protein with highest amino acid identity with the rat Oatp1. When expressed in Xenopus laevis oocytes, the mouse Oatp exhibited the same substrate specificity as the rat Oatp1. Besides the common Oatp substrates bromosulphophthalein, taurocholate, oestrone 3-sulphate and ouabain, the new mouse Oatp also mediates transport of the Oatp1-specific magnetic-resonance-imaging agent gadoxetate. The Oatp2-specific cardiac glycoside digoxin, however, is not transported. Kinetic analyses performed for taurocholate and oestrone 3-sulphate revealed apparent Km values of 12 μM and 5 μM respectively. Northern-blot analysis demonstrated a predominant expression in the liver with an additional moderate expression in the kidney. Taken together, the amino acid identity, the functional characteristics and the tissue distribution suggest that we have isolated the murine orthologue of the rat Oatp1, and consequently the identified protein will be called Oatp1. Using fluorescence in situ hybridization, the murine Oatp1 gene was mapped to chromosome XA3-A5.

scholarly journals Sedolisins, a New Class of Secreted Proteases from Aspergillus fumigatus with Endoprotease or Tripeptidyl-Peptidase Activity at Acidic pHs

2006 ◽  
Vol 72 (3) ◽  
pp. 1739-1748 ◽  
Author(s):  
Utz Reichard ◽  
Barbara Léchenne ◽  
Abdul R. Asif ◽  
Frank Streit ◽  
Eric Grouzmann ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Signal Sequence ◽  
Gene Families ◽  
Peptidase Activity ◽  
New Class ◽  
Tripeptidyl Peptidase ◽  
Genes Encoding ◽  
Member Gene ◽  
Culture Supernatants ◽  
Hydrolysis Of

ABSTRACT The secreted proteolytic activity of Aspergillus fumigatus is of potential importance as a virulence factor and in the industrial hydrolysis of protein sources. The A. fumigatus genome contains sequences that could encode a five-member gene family that produces proteases in the sedolisin family (MEROPS S53). Four putative secreted sedolisins with a predicted 17- to 20-amino-acid signal sequence were identified and termed SedA to SedD. SedA produced heterologously in Pichia pastoris was an acidic endoprotease. Heterologously produced SedB, SedC, and SedD were tripeptidyl-peptidases (TPP) with a common specificity for tripeptide-p-nitroanilide substrates at acidic pHs. Purified SedB hydrolyzed the peptide Ala-Pro-Gly-Asp-Arg-Ile-Tyr-Val-His-Pro-Phe to Arg-Pro-Gly, Asp-Arg-Ile, and Tyr-Val-His-Pro-Phe, thereby confirming TPP activity of the enzyme. SedB, SedC, and SedD were detected by Western blotting in culture supernatants of A. fumigatus grown in a medium containing hemoglobin as the sole nitrogen source. A degradation product of SedA also was observed. A search for genes encoding sedolisin homologues in other fungal genomes indicates that sedolisin gene families are widespread among filamentous ascomycetes.

scholarly journals Lytic Activity of LysH5 Endolysin Secreted by Lactococcus lactis Using the Secretion Signal Sequence of Bacteriocin Lcn972

2012 ◽  
Vol 78 (9) ◽  
pp. 3469-3472 ◽  
Author(s):  
Lorena Rodríguez-Rubio ◽  
Dolores Gutiérrez ◽  
Beatriz Martínez ◽  
Ana Rodríguez ◽  
Pilar García
Keyword(s):  
Staphylococcus Aureus ◽  
Lactococcus Lactis ◽  
Signal Peptide ◽  
Signal Sequence ◽  
Content Type ◽  
Inducible Promoters ◽  
Secretion Signal ◽  
Cell Extracts ◽  
Culture Supernatants ◽  
Secretion Signal Sequence

ABSTRACTBacteriophage endolysins have an interesting potential as antimicrobials. The endolysin LysH5, encoded byStaphylococcus aureusphage vB_SauS-phi-IPLA88, was expressed and secreted inLactococcus lactisusing the signal peptide of bacteriocin lactococcin 972 and lactococcal constitutive and inducible promoters. Up to 80 U/mg of extracellular active endolysin was detected in culture supernatants, but most of the protein (up to 323 U/mg) remained in the cell extracts.

scholarly journals Molecular cloning of two isoforms of the murine homolog of the myeloid CD33 antigen

Blood ◽  
1994 ◽  
Vol 83 (11) ◽  
pp. 3188-3198 ◽  
Author(s):  
EZ Tchilian ◽  
PC Beverley ◽  
BD Young ◽  
SM Watt
Keyword(s):  
Amino Acid ◽  
Cell Line ◽  
Myeloid Cell ◽  
Amino Acid Identity ◽  
Amino Acid Sequences ◽  
Cdna Clones ◽  
Reading Frame ◽  
Murine Homolog ◽  
Myeloid Cell Line ◽  
Nucleotide Insertion

Abstract CD33 monoclonal antibodies recognize a 67-kD glycoprotein of unknown function that is expressed by early myeloid progenitors and their leukemic counterparts. We report here the cloning of the murine homolog of the human CD33 antigen. Two cDNA clones, differing by an 83- nucleotide insertion in the cytoplasmic region, were isolated. The insertion generated a shift in the reading frame within the cytoplasmic tail, resulting in two mouse CD33 isoforms, m33-A and m33-B, with distinct cytoplasmic domains and with predicted protein core molecular weights of 37 kD and 45 kD, respectively. The cDNAs and deduced amino acid sequences show extensive similarity with the human CD33 sequence with the highest homology occurring in the first and second lg-like domains (61% amino acid identity). The most significant divergence between the human and murine proteins occurs in their cytoplasmic portions. The murine CD33 mRNAs were detected in bone marrow, spleen, thymus, brain, liver, the multipotential progenitor cell line, A4, the myelomonocytic cell line, WEHI3B, the myeloid cell line, M1, and the macrophage cell line, P388, by Northern blot analysis. The expression pattern of the murine CD33 homolog suggests that the function of CD33 antigen in hematopoiesis may be conserved between humans and mice.

scholarly journals The role of synonymous mutations in the evolution of TEM β-lactamase genes

2021 ◽  
Author(s):  
Mohammad Faheem ◽  
Charles J. Zhang ◽  
Monica N. Morris ◽  
Juergen Pleiss ◽  
Peter Oelschlaeger
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Disc Diffusion ◽  
Nucleotide Change ◽  
Nonsynonymous Mutation ◽  
Synonymous Mutations ◽  
Extended Spectrum ◽  
Genes Encoding ◽  
Variant Genes

Nonsynonymous mutations are well documented in TEM β-lactamases. The resulting amino acid changes often alter the conferred phenotype from broad spectrum (2b) conferred by TEM-1 to extended spectrum (2be), inhibitor resistant (2br), or both extended spectrum and inhibitor resistant (2ber). The encoding blaTEM genes also deviate in numerous synonymous mutations, which are not well understood. blaTEM-3 (2be), blaTEM-33 (2br), and blaTEM-109 (2ber) were studied in comparison to blaTEM-1. blaTEM-33 was chosen for more detailed studies, because it deviates from blaTEM-1 by a single nonsynonymous mutation and three additional, synonymous mutations. Genes encoding the enzymes with only nonsynonymous or all, including synonymous, mutations plus all permutations between blaTEM-1 and blaTEM-33 were expressed in Escherichia coli cells. In disc diffusion assays, genes encoding TEM-3, TEM-33, and TEM-109 with all synonymous mutations resulted in higher resistance levels than genes without synonymous mutations. Disc diffusion assays with the 16 genes carrying all possible nucleotide change combinations between blaTEM-1 and blaTEM-33 indicated different susceptibilities for different variants. Nucleotide BLAST searches did not identify genes without synonymous mutations but some without nonsynonymous mutations. Energies of possible secondary mRNA structures calculated with mfold are generally higher with synonymous mutations, suggesting that their role could be to destabilize the mRNA and facilitate its unfolding for efficient translation. In summary, our data indicate that transitions from blaTEM-1 to other variant genes by simply acquiring the nonsynonymous mutations is not favored. Instead, synonymous mutations seem to support the transition to other variant genes with nonsynonymous mutations leading to different phenotypes.

scholarly journals Cloning and Characterization of a Rhizobium leguminosarum Gene Encoding a Bacteriocin with Similarities to RTX Toxins

1999 ◽  
Vol 65 (7) ◽  
pp. 2833-2840 ◽  
Author(s):  
Ivan J. Oresnik ◽  
Sunny Twelker ◽  
Michael F. Hynes
Keyword(s):  
Amino Acid ◽  
Sinorhizobium Meliloti ◽  
Insertional Mutagenesis ◽  
Rhizobium Leguminosarum ◽  
Nodule Occupancy ◽  
Bacteriocin Activity ◽  
Gene Encoding ◽  
Reading Frame ◽  
Rtx Toxins ◽  
Culture Supernatants

ABSTRACT A 3-kb region containing the determinant for bacteriocin activity from Rhizobium leguminosarum 248 was isolated and characterized by Tn5 insertional mutagenesis and DNA sequencing. Southern hybridizations showed that this bacteriocin was encoded on the plasmid pRL1JI and that homologous loci were not found in other unrelated R. leguminosarum strains. Tn5 insertional mutagenesis showed that mutations in the C-terminal half of the bacteriocin open reading frame apparently did not abolish bacteriocin activity. Analysis of the deduced amino acid sequence revealed that, similarly to RTX proteins (such as hemolysin and leukotoxin), this protein contains a characteristic nonapeptide repeated up to 18 times within the protein. In addition, a novel 19- to 25-amino-acid motif that occurred every 130 amino acids was detected. Bacteriocin bioactivity was correlated with the presence of a protein of approximately 100 kDa in the culture supernatants, and the bacteriocin bioactivity demonstrated a calcium dependence in bothR. leguminosarum and Sinorhizobium meliloti. A mutant of strain 248 unable to produce this bacteriocin was found to have a statistically significant reduction in competitiveness for nodule occupancy compared to two test strains in coinoculation assays. However, this strain was unable to compete any more successfully with a third test strain, 3841, than was wild-type 248.

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