scholarly journals Intrachromosomal Recombination within thevsp Locus of Mycoplasma bovis Generates a Chimeric Variable Surface Lipoprotein Antigen

2001 ◽  
Vol 69 (6) ◽  
pp. 3703-3712 ◽  
Author(s):  
Inessa Lysnyansky ◽  
Yael Ron ◽  
Konrad Sachse ◽  
David Yogev
Keyword(s):  
Recombination Event ◽  
Phenotypic Switching ◽  
Upstream Region ◽  
Mycoplasma Bovis ◽  
Gene Repertoire ◽  
Genomic Locus ◽  
Chimeric Genes ◽  
C Terminus ◽  
Variable Surface ◽  
Genes Encoding

ABSTRACT A family of 13 related but divergent vsp genes was recently found in the chromosome of the bovine pathogenMycoplasma bovis. The vsp genomic locus was shown to undergo high-frequency rearrangements and to mediate phenotypic switching of variable lipoprotein antigens (Vsps) on the mycoplasma cell surface. Here we report that the vsp gene repertoire is subject to changes. Genetic analysis of M. bovis clonal isolates displaying distinct Vsp phenotypes showed that an intergenic recombination event between two closely related members of the vsp gene family, the formerly expressedvspA gene and the vspO gene, led to the formation of a new chimeric and functional vsp gene,vspC. The 5′ end of the recombination event was identified within the highly conserved vsp-upstream region, while the 3′ end was localized within the first repetitive domain (RA1) present in both vspA and vspOstructural genes. As a result, the vspC gene is an embodiment of the following domains: an N-terminus-encoding region linked to the highly conserved vsp-upstream region provided by the vspO gene; and a C-terminus-encoding region and the more distal and divergent vsp-upstream region acquired from the vspA gene. The generation of chimeric genes encoding surface antigens may provide an important element of genetic variation and an additional source of antigenic diversification within the mycoplasma population.

scholarly journals Extended Repertoire of Genes Encoding Variable Surface Lipoproteins in Mycoplasma bovis Strains

2002 ◽  
Vol 70 (4) ◽  
pp. 2220-2225 ◽  
Author(s):  
Sarit Nussbaum ◽  
Inessa Lysnyansky ◽  
Konrad Sachse ◽  
Sharon Levisohn ◽  
David Yogev
Keyword(s):  
High Frequency ◽  
Antigenic Variation ◽  
Phenotypic Switching ◽  
Mycoplasma Bovis ◽  
Structural Genes ◽  
Coding Sequences ◽  
Sequence Variations ◽  
Variable Surface ◽  
Genes Encoding ◽  
Genomic Cluster

ABSTRACT A genomic cluster of vsp genes was previously shown to mediate high-frequency phenotypic switching of surface lipoprotein antigens in the bovine pathogen Mycoplasma bovis. This study revealed that field strains of M. bovis possess modified versions of the vsp gene complex in which extensive sequence variations occur primarily in the reiterated coding sequences of the vsp structural genes. These findings demonstrate that there is a vastly expanded potential for antigenic variation within populations of this organism.

The vsp Locus of Mycoplasma bovis: Gene Organization and Structural Features

1999 ◽  
Vol 181 (18) ◽  
pp. 5734-5741 ◽  
Author(s):  
Inessa Lysnyansky ◽  
Konrad Sachse ◽  
Ricardo Rosenbusch ◽  
Sharon Levisohn ◽  
David Yogev
Keyword(s):  
High Frequency ◽  
Sequence Similarity ◽  
Membrane Surface ◽  
Amino Acid Sequences ◽  
High Rate ◽  
Phenotypic Switching ◽  
Upstream Region ◽  
Mycoplasma Bovis ◽  
High Sequence Similarity ◽  
Polypeptide Structure

ABSTRACT Major lipoprotein antigens, known as variable membrane surface lipoproteins (Vsps), on the surface of the bovine pathogenMycoplasma bovis were shown to spontaneously undergo noncoordinate phase variation between ON and OFF expression states. The high rate of Vsp phenotypic switching was also shown to be linked with DNA rearrangements that occur at high frequency in the M. bovis chromosome (I. Lysnyansky, R. Rosengarten, and D. Yogev, J. Bacteriol. 178:5395–5401, 1996). In the present study, 13 single-copyvsp genes organized in a chromosomal cluster were identified and characterized. All vsp genes encode highly conserved N-terminal domains for membrane insertion and lipoprotein processing but divergent mature Vsp proteins. About 80% of eachvsp coding region is composed of reiterated coding sequences that create a periodic polypeptide structure. Eighteen distinct repetitive domains of different lengths and amino acid sequences are distributed within the products of the variousvsp genes that are subject to size variation due to spontaneous insertions or deletions of these periodic units. Some of these repeats were found to be present in only one Vsp family member, whereas other repeats recurred at variable locations in several Vsps. Each vsp gene is also 5′ linked to a highly homologous upstream region composed of two internal cassettes. The findings that rearrangement events are associated with Vsp phenotypic switching and that multiple regions of high sequence similarity are present upstream of the vsp genes and within the vsp coding regions suggest that modulation of the Vsp antigenic repertoire is determined by recombination processes that occur at a high frequency within the vsp locus of M. bovis.

scholarly journals A Deadly Cargo: Gene Repertoire of Cytotoxic Effector Proteins in the Camelidae

Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 304
Author(s):  
Ján Futas ◽  
Jan Oppelt ◽  
Pamela Anna Burger ◽  
Petr Horin
Keyword(s):  
Cytotoxic T Cells ◽  
Effector Proteins ◽  
Target Cells ◽  
Gene Repertoire ◽  
Interspecific Differences ◽  
Genes Encoding ◽  
Bactrian Camels ◽  
Pore Forming Proteins ◽  
Sequence Similarities ◽  
Cytotoxic Effector

Cytotoxic T cells and natural killer cells can kill target cells based on their expression and release of perforin, granulysin, and granzymes. Genes encoding these molecules have been only poorly annotated in camelids. Based on bioinformatic analyses of genomic resources, sequences corresponding to perforin, granulysin, and granzymes were identified in genomes of camelids and related ungulate species, and annotation of the corresponding genes was performed. A phylogenetic tree was constructed to study evolutionary relationships between the species analyzed. Re-sequencing of all genes in a panel of 10 dromedaries and 10 domestic Bactrian camels allowed analyzing their individual genetic polymorphisms. The data showed that all extant Old World camelids possess functional genes for two pore-forming proteins (PRF1, GNLY) and six granzymes (GZMA, GZMB, GZMH, GZMK, GZMM, and GZMO). All these genes were represented as single copies in the genome except the GZMH gene exhibiting interspecific differences in the number of loci. High protein sequence similarities with other camelid and ungulate species were observed for GZMK and GZMM. The protein variability in dromedaries and Bactrian camels was rather low, except for GNLY and chymotrypsin-like granzymes (GZMB, GZMH).

scholarly journals Putative VanRS-Like Two-Component Regulatory System Associated with the Inducible Glycopeptide Resistance Cluster of Paenibacillus popilliae

2005 ◽  
Vol 49 (7) ◽  
pp. 2625-2633 ◽  
Author(s):  
Henry Fraimow ◽  
Christopher Knob ◽  
Inmaculada A. Herrero ◽  
Robin Patel
Keyword(s):  
Regulatory System ◽  
Growth Curves ◽  
Upstream Region ◽  
Bacillus Halodurans ◽  
Human Pathogens ◽  
Glycopeptide Resistance ◽  
Transposase Gene ◽  
Two Component ◽  
Genes Encoding ◽  
Paenibacillus Lentimorbus

ABSTRACT Paenibacillus popilliae contains vanF encoding a putative d-Ala:d-lactate (d-Lac) ligase, VanF, as part of the vanY F Z F H F FX F cluster that is similar in structure to the enterococcal vanA and vanB clusters. Using growth curves, we demonstrated that vancomycin resistance in P. popilliae is inducible. Using degenerate oligonucleotides targeted at bacterial cell wall ligases, we identified a second ligase gene with features of a d-Ala:d-Ala ligase in both P. popilliae and the related, vancomycin-susceptible, Paenibacillus lentimorbus. The 3,380-bp region upstream of vanY F Z F H F FX F in P. popilliae ATCC 14706 was sequenced and found to contain genes encoding a putative two-component regulator, VanRFSF, similar to VanRS but more closely related to a family of two-component regulators linked to VanY-like carboxypeptidases in several glycopeptide-susceptible Bacillus species. This upstream region also included a transposase similar to a transposase found in Bacillus halodurans and, in some strains, a 99-bp insertion of unknown function with 95% nucleotide identity to a portion of the Tn1546 transposase gene. Analysis of glycopeptide resistance-associated clusters from soil and/or insect-dwelling organisms may provide important clues to the molecular evolution of acquired glycopeptide resistance elements in human pathogens.

scholarly journals Whole-Genome Sequence of Mycoplasma bovis Strain Ningxia-1

2018 ◽  
Vol 6 (4) ◽  
Author(s):  
Peng Sun ◽  
Haifeng Luo ◽  
Xin Zhang ◽  
Jingyi Xu ◽  
Yanan Guo ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Single Molecule ◽  
Whole Genome Sequence ◽  
Mycoplasma Bovis ◽  
Sequencing Technology ◽  
Circular Chromosome ◽  
A Genome ◽  
Variable Surface ◽  
Integrative Conjugative Elements ◽  
Single Circular Chromosome

ABSTRACT A genome sequence of the Mycoplasma bovis Ningxia-1 strain was tested by Pacific Biosciences (PacBio) single-molecule real-time (SMRT) sequencing technology. The strain was isolated from a lesioned calf lung in 2013 in Pengyang, Ningxia, China. The single circular chromosome of 1,033,629 bp shows differences between complete Mycoplasma bovis genome in insertion-like sequences (ISs), integrative conjugative elements (ICEs), lipoproteins (LPs), variable surface lipoproteins (VSPs), pathogenicity islands (PAIs), etc.

scholarly journals Cloning and Characterization of Two Xyloglucanases from Paenibacillus sp. Strain KM21

2005 ◽  
Vol 71 (12) ◽  
pp. 7670-7678 ◽  
Author(s):  
Katsuro Yaoi ◽  
Tomonori Nakai ◽  
Yoshiro Kameda ◽  
Ayako Hiyoshi ◽  
Yasushi Mitsuishi
Keyword(s):  
Glycoside Hydrolase ◽  
Amino Acid Sequences ◽  
Glycoside Hydrolase Family ◽  
Carbohydrate Binding ◽  
Carbohydrate Binding Module ◽  
C Terminus ◽  
Paenibacillus Sp ◽  
Genes Encoding ◽  
Molecular Masses

ABSTRACT Two xyloglucan-specific endo-β-1,4-glucanases (xyloglucanases [XEGs]), XEG5 and XEG74, with molecular masses of 40 kDa and 105 kDa, respectively, were isolated from the gram-positive bacterium Paenibacillus sp. strain KM21, which degrades tamarind seed xyloglucan. The genes encoding these XEGs were cloned and sequenced. Based on their amino acid sequences, the catalytic domains of XEG5 and XEG74 were classified in the glycoside hydrolase families 5 and 74, respectively. XEG5 is the first xyloglucanase belonging to glycoside hydrolase family 5. XEG5 lacks a carbohydrate-binding module, while XEG74 has an X2 module and a family 3 type carbohydrate-binding module at its C terminus. The two XEGs were expressed in Escherichia coli, and recombinant forms of the enzymes were purified and characterized. Both XEGs had endoglucanase active only toward xyloglucan and not toward Avicel, carboxymethylcellulose, barley β-1,3/1,4-glucan, or xylan. XEG5 is a typical endo-type enzyme that randomly cleaves the xyloglucan main chain, while XEG74 has dual endo- and exo-mode activities or processive endo-mode activity. XEG5 digested the xyloglucan oligosaccharide XXXGXXXG to produce XXXG, whereas XEG74 digestion of XXXGXXXG resulted in XXX, XXXG, and GXXXG, suggesting that this enzyme cleaves the glycosidic bond of unbranched Glc residues. Analyses using various oligosaccharide structures revealed that unique structures of xyloglucan oligosaccharides can be prepared with XEG74.

scholarly journals Faustovirus, an Asfarvirus-Related New Lineage of Giant Viruses Infecting Amoebae

2015 ◽  
Vol 89 (13) ◽  
pp. 6585-6594 ◽  
Author(s):  
Dorine Gaëlle Reteno ◽  
Samia Benamar ◽  
Jacques Bou Khalil ◽  
Julien Andreani ◽  
Nicholas Armstrong ◽  
...  
Keyword(s):  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Open Reading Frames ◽  
Gene Repertoire ◽  
Significant Similarity ◽  
Content Type ◽  
Genes Encoding ◽  
Giant Viruses ◽  
Almost All

ABSTRACTGiant viruses are protist-associated viruses belonging to the proposed orderMegavirales; almost all have been isolated fromAcanthamoebaspp. Their isolation in humans suggests that they are part of the human virome. Using a high-throughput strategy to isolate new giant viruses from their original protozoan hosts, we obtained eight isolates of a new giant viral lineage fromVermamoebavermiformis, the most common free-living protist found in human environments. This new lineage was proposed to be the faustovirus lineage. The prototype member, faustovirus E12, forms icosahedral virions of ≈200 nm that are devoid of fibrils and that encapsidate a 466-kbp genome encoding 451 predicted proteins. Of these, 164 are found in the virion. Phylogenetic analysis of the core viral genes showed that faustovirus is distantly related to the mammalian pathogen African swine fever virus, but it encodes ≈3 times more mosaic gene complements. About two-thirds of these genes do not show significant similarity to genes encoding any known proteins. These findings show that expanding the panel of protists to discover new giant viruses is a fruitful strategy.IMPORTANCEBy usingVermamoeba, a protist living in humans and their environment, we isolated eight strains of a new giant virus that we named faustovirus. The genomes of these strains were sequenced, and their sequences showed that faustoviruses are related to but different from the vertebrate pathogen African swine fever virus (ASFV), which belongs to the familyAsfarviridae. Moreover, the faustovirus gene repertoire is ≈3 times larger than that of ASFV and comprises approximately two-thirds ORFans (open reading frames [ORFs] with no detectable homology to other ORFs in a database).

scholarly journals Nisin-Controlled Production of Pediocin PA-1 and Colicin V in Nisin- and Non-Nisin-Producing Lactococcus lactis Strains

2004 ◽  
Vol 70 (8) ◽  
pp. 5030-5032 ◽  
Author(s):  
Nikki Horn ◽  
Antonio Fernández ◽  
Helen M. Dodd ◽  
Michael J. Gasson ◽  
Juan M. Rodríguez
Keyword(s):  
Lactococcus Lactis ◽  
Chimeric Genes ◽  
Two Component ◽  
Genes Encoding ◽  
Colicin V ◽  
Nisin Producer

ABSTRACT The introduction of chimeric genes encoding the fusion leader of lactococcin A-propediocin PA-1 or procolicin V under the control of the inducible nisA promoter and the lactococcin A-dedicated secretion genes (lcnCD) into Lactococcus lactis strains, including a nisin producer, expressing the two component regulator NisRK led to the production or pediocin PA-1 or colicin V, respectively.

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