scholarly journals Identification and characterization of Fep15, a new selenocysteine-containing member of the Sep15 protein family

2006 ◽  
Vol 394 (3) ◽  
pp. 575-579 ◽  
Author(s):  
Sergey V. Novoselov ◽  
Deame Hua ◽  
Alexey V. Lobanov ◽  
Vadim N. Gladyshev
Keyword(s):  
Mammalian Cells ◽  
Insertion Sequence ◽  
Phylogenetic Analyses ◽  
Dependent Manner ◽  
Putative Active Site ◽  
A Genome ◽  
Sequence Elements ◽  
Identification And Characterization ◽  
Insertion Sequence Elements

Sec (selenocysteine) is a rare amino acid in proteins. It is co-translationally inserted into proteins at UGA codons with the help of SECIS (Sec insertion sequence) elements. A full set of selenoproteins within a genome, known as the selenoproteome, is highly variable in different organisms. However, most of the known eukaryotic selenoproteins are represented in the mammalian selenoproteome. In addition, many of these selenoproteins have cysteine orthologues. Here, we describe a new selenoprotein, designated Fep15, which is distantly related to members of the 15 kDa selenoprotein (Sep15) family. Fep15 is absent in mammals, can be detected only in fish and is present in these organisms only in the selenoprotein form. In contrast with other members of the Sep15 family, which contain a putative active site composed of Sec and cysteine, Fep15 has only Sec. When transiently expressed in mammalian cells, Fep15 incorporated Sec in an SECIS- and SBP2 (SECIS-binding protein 2)-dependent manner and was targeted to the endoplasmic reticulum by its N-terminal signal peptide. Phylogenetic analyses of Sep15 family members suggest that Fep15 evolved by gene duplication.

scholarly journals Characterization of Cyt2Bc Toxin from Bacillus thuringiensis subsp. medellin

2002 ◽  
Vol 68 (3) ◽  
pp. 1228-1231 ◽  
Author(s):  
Victor Juárez-Pérez ◽  
Alejandra Guerchicoff ◽  
Clara Rubinstein ◽  
Armelle Delécluse
Keyword(s):  
Bacillus Thuringiensis ◽  
Insertion Sequence ◽  
Anopheles Stephensi ◽  
Mosquito Species ◽  
Bacillus Sphaericus ◽  
Binary Toxin ◽  
Activation Time ◽  
Sequence Elements ◽  
Insertion Sequence Elements

ABSTRACT We cloned and sequenced a new cytolysin gene from Bacillus thuringiensis subsp. medellin. Three IS240-like insertion sequence elements and the previously cloned cyt1Ab and p21 genes were found in the vicinity of the cytolysin gene. The cytolysin gene encodes a protein 29.7 kDa in size that is 91.5% identical to Cyt2Ba from Bacillus thuringiensis subsp. israelensis and has been designated Cyt2Bc. Inclusions containing Cyt2Bc were purified from the crystal-negative strain SPL407 of B. thuringiensis. Cyt2Bc reacted weakly with antibodies directed against Cyt2Ba and was not recognized by an antiserum directed against the reference cytolysin Cyt1Aa. Cyt2Bc was hemolytic only upon activation with trypsin and had only one-third to one-fifth of the activity of Cyt2Ba, depending on the activation time. Cyt2Bc was also mosquitocidal against Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus, including strains resistant to the Bacillus sphaericus binary toxin. Its toxicity was half of that of Cyt2Ba on all mosquito species except resistant C. quinquefasciatus.

scholarly journals Characterization of the Transposase Encoded by IS256, the Prototype of a Major Family of Bacterial Insertion Sequence Elements

2010 ◽  
Vol 192 (16) ◽  
pp. 4153-4163 ◽  
Author(s):  
Susanne Hennig ◽  
Wilma Ziebuhr
Keyword(s):  
Dna Binding ◽  
Insertion Sequence ◽  
Amino Acid Residues ◽  
Left Hand ◽  
Sequence Elements ◽  
Catalytic Motif ◽  
Mutagenesis Study ◽  
Insertion Sequence Elements ◽  
Insight Into

ABSTRACT IS256 is the founding member of the IS256 family of insertion sequence (IS) elements. These elements encode a poorly characterized transposase, which features a conserved DDE catalytic motif and produces circular IS intermediates. Here, we characterized the IS256 transposase as a DNA-binding protein and obtained insight into the subdomain organization and functional properties of this prototype enzyme of IS256 family transposases. Recombinant forms of the transposase were shown to bind specifically to inverted repeats present in the IS256 noncoding regions. A DNA-binding domain was identified in the N-terminal part of the transposase, and a mutagenesis study targeting conserved amino acid residues in this region revealed a putative helix-turn-helix structure as a key element involved in DNA binding. Furthermore, we obtained evidence to suggest that the terminal nucleotides of IS256 are critically involved in IS circularization. Although small deletions at both ends reduced the formation of IS circles, changes at the left-hand IS256 terminus proved to be significantly more detrimental to circle production. Taken together, the data lead us to suggest that the IS256 transposase-mediated circularization reaction preferentially starts with a sequence-specific first-strand cleavage at the left-hand IS terminus.

scholarly journals Identification and Characterization of OscR, a Transcriptional Regulator Involved in Osmolarity Adaptation in Vibrio cholerae

2009 ◽  
Vol 191 (13) ◽  
pp. 4082-4096 ◽  
Author(s):  
Nicholas J. Shikuma ◽  
Fitnat H. Yildiz
Keyword(s):  
Vibrio Cholerae ◽  
Biofilm Formation ◽  
Transcriptional Regulator ◽  
Dependent Manner ◽  
Genome Wide ◽  
Low Salt ◽  
Adaptation Response ◽  
Matrix Production ◽  
Identification And Characterization

ABSTRACT Vibrio cholerae is a facultative human pathogen. In its aquatic habitat and as it passes through the digestive tract, V. cholerae must cope with fluctuations in salinity. We analyzed the genome-wide transcriptional profile of V. cholerae grown at different NaCl concentrations and determined that the expression of compatible solute biosynthesis and transporter genes, virulence genes, and genes involved in adhesion and biofilm formation is differentially regulated. We determined that salinity modulates biofilm formation, and this response was mediated through the transcriptional regulators VpsR and VpsT. Additionally, a transcriptional regulator controlling an osmolarity adaptation response was identified. This regulator, OscR (osmolarity controlled regulator), was found to modulate the transcription of genes involved in biofilm matrix production and motility in a salinity-dependent manner. oscR mutants were less motile and exhibited enhanced biofilm formation only under low-salt conditions.

New cfiA variant and novel insertion sequence elements in carbapenem-resistant Bacteroides fragilis isolates from Korea

2010 ◽  
Vol 66 (4) ◽  
pp. 343-348 ◽  
Author(s):  
Kyoung Ho Roh ◽  
Sinyoung Kim ◽  
Chang-Ki Kim ◽  
Jong Hwa Yum ◽  
Myung Sook Kim ◽  
...  
Keyword(s):  
Insertion Sequence ◽  
Bacteroides Fragilis ◽  
Carbapenem Resistant ◽  
Sequence Elements ◽  
Insertion Sequence Elements

scholarly journals Dynamics of Genome Architecture in Rhizobium sp. Strain NGR234

2002 ◽  
Vol 184 (1) ◽  
pp. 171-176 ◽  
Author(s):  
Patrick Mavingui ◽  
Margarita Flores ◽  
Xianwu Guo ◽  
Guillermo Dávila ◽  
Xavier Perret ◽  
...  
Keyword(s):  
Large Scale ◽  
Insertion Sequence ◽  
Biological Significance ◽  
Genome Architecture ◽  
Bacterial Genomes ◽  
Symbiotic Plasmid ◽  
Sequence Elements ◽  
Dynamic Structures ◽  
Genome Analyses ◽  
Insertion Sequence Elements

ABSTRACT Bacterial genomes are usually partitioned in several replicons, which are dynamic structures prone to mutation and genomic rearrangements, thus contributing to genome evolution. Nevertheless, much remains to be learned about the origins and dynamics of the formation of bacterial alternative genomic states and their possible biological consequences. To address these issues, we have studied the dynamics of the genome architecture in Rhizobium sp. strain NGR234 and analyzed its biological significance. NGR234 genome consists of three replicons: the symbiotic plasmid pNGR234a (536,165 bp), the megaplasmid pNGR234b (>2,000 kb), and the chromosome (>3,700 kb). Here we report that genome analyses of cell siblings showed the occurrence of large-scale DNA rearrangements consisting of cointegrations and excisions between the three replicons. As a result, four new genomic architectures have emerged. Three consisted of the cointegrates between two replicons: chromosome-pNGR234a, chromosome-pNGR234b, and pNGR234a-pNGR234b. The other consisted of a cointegrate of the three replicons (chromosome-pNGR234a-pNGR234b). Cointegration and excision of pNGR234a with either the chromosome or pNGR234b were studied and found to proceed via a Campbell-type mechanism, mediated by insertion sequence elements. We provide evidence showing that changes in the genome architecture did not alter the growth and symbiotic proficiency of Rhizobium derivatives.

scholarly journals Identification and Characterization of Four Autophagy-Related Genes That Are Expressed in Response to Hypoxia in the Brain of the Oriental River Prawn (Macrobrachium nipponense)

2019 ◽  
Vol 20 (8) ◽  
pp. 1856 ◽  
Author(s):  
Shengming Sun ◽  
Ying Wu ◽  
Hongtuo Fu ◽  
Xianping Ge ◽  
Hongzheng You ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Open Reading Frames ◽  
Dependent Manner ◽  
Macrobrachium Nipponense ◽  
Oriental River Prawn ◽  
Adverse Environmental Conditions ◽  
The Brain ◽  
Identification And Characterization

Autophagy is a cytoprotective mechanism triggered in response to adverse environmental conditions. Herein, we investigated the autophagy process in the oriental river prawn (Macrobrachium nipponense) following hypoxia. Full-length cDNAs encoding autophagy-related genes (ATGs) ATG3, ATG4B, ATG5, and ATG9A were cloned, and transcription following hypoxia was explored in different tissues and developmental stages. The ATG3, ATG4B, ATG5, and ATG9A cDNAs include open reading frames encoding proteins of 319, 264, 268, and 828 amino acids, respectively. The four M. nipponense proteins clustered separately from vertebrate homologs in phylogenetic analysis. All four mRNAs were expressed in various tissues, with highest levels in brain and hepatopancreas. Hypoxia up-regulated all four mRNAs in a time-dependent manner. Thus, these genes may contribute to autophagy-based responses against hypoxia in M. nipponense. Biochemical analysis revealed that hypoxia stimulated anaerobic metabolism in the brain tissue. Furthermore, in situ hybridization experiments revealed that ATG4B was mainly expressed in the secretory and astrocyte cells of the brain. Silencing of ATG4B down-regulated ATG8 and decreased cell viability in juvenile prawn brains following hypoxia. Thus, autophagy is an adaptive response protecting against hypoxia in M. nipponense and possibly other crustaceans. Recombinant MnATG4B could interact with recombinant MnATG8, but the GST protein could not bind to MnATG8. These findings provide us with a better understanding of the fundamental mechanisms of autophagy in prawns.

Two identical nonylphenol monooxygenase genes linked to IS6100 and some putative insertion sequence elements in Sphingomonas sp. NP5

Microbiology ◽  
2012 ◽  
Vol 158 (7) ◽  
pp. 1796-1807 ◽  
Author(s):  
Masahiro Takeo ◽  
Yoshihiro Maeda ◽  
Junko Maeda ◽  
Naoki Nishiyama ◽  
Chitoshi Kitamura ◽  
...  
Keyword(s):  
Insertion Sequence ◽  
Sequence Elements ◽  
Insertion Sequence Elements
Sign in / Sign up

Export Citation Format

Share Document