scholarly journals Isolation and Characterization of IS1409, an Insertion Element of 4-Chlorobenzoate-DegradingArthrobacter sp. Strain TM1, and Development of a System for Transposon Mutagenesis

2001 ◽  
Vol 183 (12) ◽  
pp. 3729-3736 ◽  
Author(s):  
Karl-Heinz Gartemann ◽  
Rudolf Eichenlaub
Keyword(s):  
Resistance Genes ◽  
Micrococcus Luteus ◽  
Transposon Mutagenesis ◽  
Open Reading Frame ◽  
Insertion Element ◽  
Reading Frame ◽  
Isolation And Characterization ◽  
Insertion Elements

ABSTRACT A new insertion element of 1,449 bp with 25-bp perfect terminal repeats, designated IS1409, was identified in the chromosome of 4-chlorobenzoate-degrading Arthrobactersp. strain TM1 NCIB12013. Upon insertion, IS1409 causes a target duplication of 8 bp. IS1409 carries only a single open reading frame of 435 codons encoding the transposase TnpA. Both TnpA and the overall organization of IS1409are highly similar to those of some related insertion elements of the ISL3 group (J. Mahillon and M. Chandler, Microbiol. Mol. Biol. Rev. 62:725–774, 1998). IS1409 was also found in other 4-chlorobenzoate-degrading Arthrobacter strains and Micrococcus luteus. Based on IS1409, a series of transposons carrying resistance genes for chloramphenicol and gentamicin were constructed. These transposons were used to demonstrate transposition events in vivo and to mutagenizeArthrobacter sp. strains.

scholarly journals Isolation and Characterization of FecA- and FeoB-Mediated Iron Acquisition Systems of the Spirochete Leptospira biflexa by Random Insertional Mutagenesis

2005 ◽  
Vol 187 (9) ◽  
pp. 3249-3254 ◽  
Author(s):  
Hélène Louvel ◽  
Isabelle Saint Girons ◽  
Mathieu Picardeau
Keyword(s):  
Insertional Mutagenesis ◽  
Iron Acquisition ◽  
Transposon Mutagenesis ◽  
Ecological Niches ◽  
Acid Biosynthesis ◽  
Gene Encoding ◽  
Isolation And Characterization ◽  
Transposon Mutants

ABSTRACT The specific mechanisms by which Leptospira spp. acquire iron from their ecological niches are unknown. A major factor contributing to our ignorance of spirochetal biology is the lack of methods for genetic analysis of these organisms. In this study, we have developed a system for random transposon mutagenesis of Leptospira biflexa using a mariner transposon, Himar1. To demonstrate the validity of Himar1 in vivo transposon mutagenesis in L. biflexa, a screen of mutants for clones impaired in amino acid biosynthesis was first performed, enabling the identification of tryptophan and glutamate auxotrophs. To investigate iron transporters, 2,000 L. biflexa transposon mutants were screened onto media with and without hemin, thus allowing the identification of five hemin-requiring mutants, and the putative genes responsible for this phenotype were identified. Three mutants had distinct insertions in a gene encoding a protein which shares homology with the TonB-dependent receptor FecA, involved in ferric citrate transport. We also identified two mutants with a Himar1 insertion into a feoB-like gene, the product of which is required for ferrous iron uptake in many bacterial organisms. Interestingly, the growth inhibition exhibited by the fecA and feoB mutants was relieved by deferoxamine, suggesting the presence of a ferric hydroxamate transporter. These results confirm the importance of iron for the growth of Leptospira and its ability to use multiple iron sources.

scholarly journals Isolation and Characterization of Canthaxanthin Biosynthesis Genes from the Photosynthetic Bacterium Bradyrhizobiumsp. Strain ORS278

2000 ◽  
Vol 182 (13) ◽  
pp. 3850-3853 ◽  
Author(s):  
Laure Hannibal ◽  
Jean Lorquin ◽  
Nicolas Angles D'Ortoli ◽  
Nelly Garcia ◽  
Clemence Chaintreuil ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Photosynthetic Bacterium ◽  
Carotenoid Biosynthesis ◽  
Open Reading Frame ◽  
Biosynthesis Gene Cluster ◽  
Reading Frame ◽  
Functional Assignment ◽  
Isolation And Characterization ◽  
Biosynthesis Gene

ABSTRACT A carotenoid biosynthesis gene cluster involved in canthaxanthin production was isolated from the photosyntheticBradyrhizobium sp. strain ORS278. This cluster includes five genes identified as crtE, crtY,crtI, crtB, and crtW that are organized in at least two operons. The functional assignment of each open reading frame was confirmed by complementation studies.

Cloning and characterization of theddsAgene encoding decaprenyl diphosphate synthase fromRhodobacter capsulatusB10

2006 ◽  
Vol 52 (12) ◽  
pp. 1141-1147 ◽  
Author(s):  
Xinyi Liu ◽  
Haizhen Wu ◽  
Jiang Ye ◽  
Qinsheng Yuan ◽  
Huizhan Zhang
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Rhodobacter Capsulatus ◽  
Open Reading Frame ◽  
High Similarity ◽  
Reading Frame ◽  
Endogenous Production ◽  
Genome Library

A decaprenyl diphosphate synthase gene (ddsA, GenBank accession No. DQ191802) was cloned from Rhodobacter capsulatus B10 by constructing and screening the genome library. An open reading frame of 1002 bp was revealed from sequence analysis. The deduced polypeptide consisted of 333 amino acids residues with an molecular mass of about 37 kDa. The DdsA protein contained the conserved amino acid sequence (DDXXD) of E-type polyprenyl diphosphate synthase and showed high similarity to others. In contrast, DdsA showed only 39% identity to a solanesyl diphosphate synthase cloned from R. capsulatus SB1003. DdsA was expressed successfully in Escherichia coli. Assaying the enzyme in vivo found it made E.coli synthesize UQ-10 in addition to the endogenous production UQ-8.Key words: ubiquinone, polyprenyl diphosphate synthase, gene expression, Rhodobacter capsulatus.

scholarly journals Isolation and Characterization of Antibacterial Carotane Sesquiterpenes from Artemisia argyi Associated Endophytic Trichoderma virens QA-8

Antibiotics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 213
Author(s):  
Xiao-Shan Shi ◽  
Yin-Ping Song ◽  
Ling-Hong Meng ◽  
Sui-Qun Yang ◽  
Dun-Jia Wang ◽  
...  
Keyword(s):  
Endophytic Fungus ◽  
Micrococcus Luteus ◽  
Crystallographic Analysis ◽  
Medicinal Herb ◽  
Trichoderma Virens ◽  
Isolation And Characterization ◽  
Artemisia Argyi ◽  
Detailed Interpretation ◽  
Fungal Kingdom

Carotane sesquiterpenes are commonly found in plants but are infrequently reported in the fungal kingdom. Chemical investigation of Trichoderma virens QA-8, an endophytic fungus associated with the inner root tissue of the grown medicinal herb Artemisia argyi H. Lév. and Vaniot, resulted in the isolation and characterization of five new carotane sesquiterpenes trichocarotins I–M (1–5), which have diverse substitution patterns, and seven known related analogues (6–12). The structures of these compounds were established on the basis of a detailed interpretation of their NMR and mass spectroscopic data, and the structures including the relative and absolute configurations of compounds 1–3, 5, 9, and 10 were confirmed by X-ray crystallographic analysis. In the antibacterial assays, all isolates exhibited potent activity against Escherichia coli EMBLC-1, with MIC values ranging from 0.5 to 32 µg/mL, while 7β-hydroxy CAF-603 (7) strongly inhibited Micrococcus luteus QDIO-3 (MIC = 0.5 µg/mL). Structure-activity relationships of these compounds were discussed. The results from this study demonstrate that the endophytic fungus T. virens QA-8 from the planted medicinal herb A. argyi is a rich source of antibacterial carotane sesquiterpenes, and some of them might be interesting for further study to be developed as novel antibacterial agents.

scholarly journals Antigenic Characterization of ORF2 and ORF3 Proteins of Hepatitis E Virus (HEV)

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1385
Author(s):  
Giulia Pezzoni ◽  
Lidia Stercoli ◽  
Eleonora Pegoiani ◽  
Emiliana Brocchi
Keyword(s):  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Recombinant Antigen ◽  
Open Reading Frame ◽  
Reading Frame ◽  
E Coli ◽  
Antigenic Characterization ◽  
Antigenic Properties ◽  
Open Reading Frame 2

To evaluate the antigenic properties of Hepatitis E Virus (HEV) Open Reading Frame 2 and 3 (ORF2 and ORF3) codified proteins, we expressed different portions of ORF2 and the entire ORF3 in E. coli, a truncated ORF2, was also expressed in baculovirus. A panel of 37 monoclonal antibodies (MAbs) was raised against ORF2 (1–660 amino acids) and MAbs were mapped and characterized using the ORF2 expressed portions. Selected HEV positive and negative swine sera were used to evaluate ORF2 and ORF3 antigens’ immunogenicity. The MAbs were clustered in six groups identifying six antigenic regions along the ORF2. Only MAbs binding to the sixth ORF2 antigenic region (394–608 aa) were found to compete with HEV positive sera and efficiently catch the recombinant antigen expressed in baculovirus. The ORF2 portion from 394–608 aa demonstrated to include most immunogenic epitopes with 85% of HEV positive swine sera reacting against the region from 461–544 aa. Only 5% of the selected HEV sera reacted against the ORF3 antigen.

scholarly journals Molecular cloning and analysis of l(1)ogre, a locus of Drosophila melanogaster with prominent effects on the postembryonic development of the central nervous system.

Genetics ◽  
1990 ◽  
Vol 126 (4) ◽  
pp. 1033-1044 ◽  
Author(s):  
T Watanabe ◽  
D R Kankel
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Postembryonic Development ◽  
P Element ◽  
Reading Frame ◽  
Isolation And Characterization ◽  
The Central Nervous System ◽  
Highly Hydrophobic ◽  
Conceptual Translation

Abstract Previous genetic studies have shown that wild-type function of the l(1)ogre (lethal (1) optic ganglion reduced) locus is essential for the generation and/or maintenance of the postembryonic neuroblasts including those from which the optic lobe is descended. In the present study molecular isolation and characterization of the l(1)ogre locus was carried out to study the structure and expression of this gene in order to gain information about the nature of l(1)ogre function and its relevance to the development of the central nervous system. About 70 kilobases (kb) of genomic DNA were isolated that spanned the region where l(1)ogre was known to reside. Southern analysis of a l(1)ogre mutation and subsequent P element-mediated DNA transformation mapped the l(1)ogre+ function within a genomic fragment of 12.5 kb. Northern analyses showed that a 2.9-kb message transcribed from this 12.5-kb region represented l(1)ogre. A 2.15-kb portion of a corresponding cDNA clone was sequenced. An open reading frame (ORF) of 1,086 base paris was found, and a protein sequence of 362 amino acids with one highly hydrophobic segment was deduced from conceptual translation of this ORF.

Sign in / Sign up

Export Citation Format

Share Document