Structural Features of the mdg1 Lineage of the Ty3/gypsy Group of LTR Retrotransposons Inferred from the Phylogenetic Analyses of Its Open Reading Frames

2001 ◽  
Vol 53 (3) ◽  
pp. 165-171 ◽  
Author(s):  
Javier Costas ◽  
Emilio Valadé ◽  
Horacio Naveira
Genetics ◽  
2001 ◽  
Vol 159 (3) ◽  
pp. 1103-1115 ◽  
Author(s):  
Hongguang Shao ◽  
Zhijian Tu

Abstract A novel transposon named ITmD37E was discovered in a wide range of mosquito species. Sequence analysis of multiple copies in three Aedes species showed similar terminal inverted repeats and common putative TA target site duplications. The ITmD37E transposases contain a conserved DD37E catalytic motif, which is unique among reported transposons of the IS630-Tc1-mariner superfamily. Sequence comparisons and phylogenetic analyses suggest that ITmD37E forms a novel family distinct from the widely distributed Tc1 (DD34E), mariner (DD34D), and pogo (DDxD) families in the IS630-Tc1-mariner superfamily. The inclusion in the phylogenetic analysis of recently reported transposons and transposons uncovered in our database survey provided revisions to previous classifications and identified two additional families, ITmD37D and ITmD39D, which contain DD37D and DD39D motifs, respectively. The above expansion and reorganization may open the doors to the discovery of related transposons in a broad range of organisms and help illustrate the evolution and structure-function relationships among these distinct transposases in the IS630-Tc1-mariner superfamily. The presence of intact open reading frames and highly similar copies in some of the newly characterized transposons suggests recent transposition. Studies of these novel families may add to the limited repertoire of transgenesis and mutagenesis tools for a wide range of organisms, including the medically important mosquitoes.


2002 ◽  
Vol 76 (7) ◽  
pp. 3382-3387 ◽  
Author(s):  
Marilyn J. Roossinck

ABSTRACT Cucumber mosaic virus (CMV) is an RNA plant virus with a tripartite genome and an extremely broad host range. Previous evolutionary analyses with the coat protein (CP) and 5′ nontranslated region (NTR) of RNA 3 suggested subdivision of the virus into three groups, subgroups IA, IB, and II. In this study 15 strains of CMV whose nucleotide sequences have been determined were used for a complete phylogenetic analysis of the virus. The trees estimated for open reading frames (ORFs) located on the different RNAs were not congruent and did not completely support the subgrouping indicated by the CP ORF, indicating that different RNAs had independent evolutionary histories. This is consistent with a reassortment mechanism playing an important role in the evolution of the virus. The evolutionary trees of the 1a and 3a ORFs were more compact and displayed more branching than did those of the 2a and CP ORFs. This may reflect more rigid host-interactive constraints exerted on the 1a and 3a ORFs. In addition, analysis of the 3′ NTR that is conserved among all RNAs indicated that evolutionary constraints on this region are specific to the RNA component rather than the virus isolate. This indicates that functions other than replication are encoded in the 3′ NTR. Reassortment may have led to the genetic diversity found among CMV strains and contributed to its enormous evolutionary success.


2020 ◽  
Author(s):  
Armelle Marais ◽  
Sergio Murolo ◽  
Chantal Faure ◽  
Yoann Brans ◽  
Clement Larue ◽  
...  

Although the chestnut mosaic disease (ChMD) was described several decades ago, its etiology is still not elucidated. Here, using classical approaches in combination with high throughput sequencing (HTS) techniques, we identify a novel Badnavirus that is a strong etiological candidate for ChMD. Two disease sources from Italy and France were submitted to HTS-based viral indexing. Total RNAs were extracted, ribodepleted and sequenced on an Illumina NextSeq500 (2x150 or 2x 75 nt). In each source, we identified a single contig of about 7.2 kilobases that corresponds to a complete circular viral genome and shares homologies with various badnaviruses. The genomes of the two isolates have an average nucleotide identity of 90.5% with a typical badnaviral genome organization comprising three open reading frames. Phylogenetic analyses and sequence comparisons show that this virus is a novel species for which we propose the name Chestnut mosaic virus (ChMV). Using a newly developed molecular detection test, we systematically detected the virus in symptomatic graft-inoculated indicator plants (chestnut and American oak), as well in chestnut trees presenting typical ChMD symptoms in the field (100% and 87% in France and Italy surveys, respectively). Datamining of publicly available chestnut SRA transcriptomic data allowed the reconstruction of two additional complete ChMV genomes from two Castanea mollissima sources from the USA, as well as ChMV detection in C. dentata from the USA. Preliminary epidemiological studies, performed in France and in Central Eastern Italy, showed that ChMV has a high incidence in some commercial orchards, with a low within-orchard genetic diversity.


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Vladimir Egorov ◽  
Natalia Grudinina ◽  
Andrey Vasin ◽  
Dmitry Lebedev

Changes in protein conformation can occur both as part of normal protein functioning and during disease pathogenesis. The most common conformational diseases are amyloidoses. Sometimes the development of a number of diseases which are not traditionally related to amyloidoses is associated with amyloid-like conformational transitions of proteins. Also, amyloid-like aggregates take part in normal physiological processes such as memorization and cell signaling. Several primary structural features of a protein are involved in conformational transitions. Also the protein proteolytic fragments can cause the conformational transitions in the protein. Short peptides which could be produced during the protein life cycle or which are encoded by short open reading frames can affect the protein conformation and function.


2007 ◽  
Vol 6 (11) ◽  
pp. 2102-2111 ◽  
Author(s):  
Javier Botet ◽  
Laura Mateos ◽  
José L. Revuelta ◽  
María A. Santos

ABSTRACT Large-scale phenotypic analyses have proved to be useful strategies in providing functional clues about the uncharacterized yeast genes. We used here a chemogenomic profiling of yeast deletion collections to identify the core of cellular processes challenged by treatment with the p-aminobenzoate/folate antimetabolite sulfanilamide. In addition to sulfanilamide-hypersensitive mutants whose deleted genes can be categorized into a number of groups, including one-carbon related metabolism, vacuole biogenesis and vesicular transport, DNA metabolic and cell cycle processes, and lipid and amino acid metabolism, two uncharacterized open reading frames (YHI9 and YMR289w) were also identified. A detailed characterization of YMR289w revealed that this gene was required for growth in media lacking p-aminobenzoic or folic acid and encoded a 4-amino-4-deoxychorismate lyase, which is the last of the three enzymatic activities required for p-aminobenzoic acid biosynthesis. In light of these results, YMR289w was designated ABZ2, in accordance with the accepted nomenclature. ABZ2 was able to rescue the p-aminobenzoate auxotrophy of an Escherichia coli pabC mutant, thus demonstrating that ABZ2 and pabC are functional homologues. Phylogenetic analyses revealed that Abz2p is the founder member of a new group of fungal 4-amino-4-deoxychorismate lyases that have no significant homology to its bacterial or plant counterparts. Abz2p appeared to form homodimers and dimerization was indispensable for its catalytic activity.


Plant Disease ◽  
2019 ◽  
Vol 103 (6) ◽  
pp. 1302-1308 ◽  
Author(s):  
Nomatter Chingandu ◽  
Lelia Dongo ◽  
Osman A. Gutierrez ◽  
Judith K. Brown

Cacao swollen shoot disease (CSSD) of Theobroma cacao was reported in Nigeria in 1944; however, no badnaviral genome sequences have been found associated with the symptomatic trees. In 2017, leaf samples (n = 18) were collected from cacao trees from Osun and Oyo, Nigeria showing foliar symptoms that included red vein-banding and shoot swelling, and variable secondary mosaic, mottling, and fern-like pattern symptoms. Abutting primers designed around previously determined 500-bp intergenic region sequences were used for polymerase chain reaction (PCR) amplification. Of the 18 samples, 9 yielded an approximately 7,000-bp, apparently genome-size product. The nine genomes were sequenced and found to encode four open reading frames, and to share 86 to 99% nucleotide identity. Pairwise analysis of the Nigerian genomes with 21 previously reported CSSD badnaviruses, at the complete genome and reverse-transcription ribonuclease H (1,230 bp) sequence levels, indicated 71 to 75 and 72 to 76% nucleotide identity, respectively. Phylogenetic analysis of the nine complete genomes indicated that the closest relatives of the divergent Nigerian isolates were previously described West African CSSD badnaviruses. Based on pairwise comparisons and phylogenetic analyses, the Nigerian CSSD isolates constitute a previously unrecognized Badnavirus sp., herein named Cacao red vein-banding virus (CRVBV). Primers designed based on the CRVBV genome sequences amplified a 1,068-bp fragment from 16 of 18 field samples tested by PCR, suggesting the possible existence of additional CRVBV variants.


2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Anouk Willemsen ◽  
Alexander van den Boom ◽  
Julienne Dietz ◽  
Seval Bilge Dagalp ◽  
Firat Dogan ◽  
...  

Abstract Background Papillomaviruses (PVs) infecting artiodactyls are very diverse, and only second in number to PVs infecting primates. PVs associated to lesions in economically important ruminant species have been isolated from cattle and sheep. Methods Potential PV DNA from teat lesions of a Damascus goat was isolated, cloned and sequenced. The PV genome was analyzed using bioinformatics approaches to detect open reading frames and to predict potential features of encoded proteins as well as putative regulatory elements. Sequence comparison and phylogenetic analyses using the concatenated E1E2L2L1 nucleotide and amino acid alignments was used to reveal the relationship of the new PV to the known PV diversity and its closest relevants. Results We isolated and characterized the full-genome of novel Capra hircus papillomavirus. We identified the E6, E7, E1, E2, L2, L1 open reading frames with protein coding potential and putative active elements in the ChPV2 proteins and putative regulatory genome elements. Sequence similarities of L1 and phylogenetic analyses using concatenated E1E2L2L1 nucleotide and amino acid alignments suggest the classification as a new PV type designated ChPV2 with a phylogenetic position within the XiPV genus, basal to the XiPV1 species. ChPV2 is not closely related to ChPV1, the other known goat PV isolated from healthy skin, although both of them belong confidently into a clade composed of PVs infecting cervids and bovids. Interestingly, ChPV2 contains an E6 open reading frame whereas all closely related PVs do not Conclusion ChPV2 is a novel goat PV closely related to the Xi-PV1 species infecting bovines. Phylogenetic relationships and genome architecture of ChPV2 and closely related PV types suggest at least two independent E6 losses within the XiPV clade.


2020 ◽  
Vol 12 (5) ◽  
pp. 578-588 ◽  
Author(s):  
Ruo-Lin Cheng ◽  
Xiao-Feng Li ◽  
Chuan-Xi Zhang

Abstract Endogenous viral elements (EVEs), derived from all major types of viruses, have been discovered in many eukaryotic genomes, representing “fossil records” of past viral infections. The endogenization of nudiviruses has been reported in several insects, leading to the question of whether genomic integration is a common phenomenon for these viruses. In this study, genomic assemblies of insects and other arthropods were analyzed to identify endogenous sequences related to Nudiviridae. A total of 359 nudivirus-like genes were identified in 43 species belonging to different groups; however, none of these genes were detected in the known hosts of nudiviruses. A large proportion of the putative EVEs identified in this study encode intact open reading frames or are transcribed as mRNAs, suggesting that they result from recent endogenization of nudiviruses. Phylogenetic analyses of the identified EVEs and inspections of their flanking regions indicated that integration of nudiviruses has occurred recurrently during the evolution of arthropods. This is the first report of a comprehensive screening for nudivirus-derived EVEs in arthropod genomes. The results of this study demonstrated that a large variety of arthropods, especially hemipteran and hymenopteran insects, have previously been or are still infected by nudiviruses. These findings have greatly extended the host range of Nudiviridae and provide new insights into viral diversity, evolution, and host–virus interactions.


1995 ◽  
Vol 15 (8) ◽  
pp. 4545-4552 ◽  
Author(s):  
S Okazaki ◽  
H Ishikawa ◽  
H Fujiwara

We characterized TRAS1, a retrotransposable element which was inserted into the telomeric repetitive sequence (CCTAA)n of the silkworm, Bombyx mori. The complete sequence of TRAS1, a stretch of 7.8 kb with a poly(A) tract at the 3' end, was determined. No long terminal repeat (LTR) was found at the termini of the element. TRAS1 contains gag- and pol-like open reading frames (ORFs) which are similar to those of non-LTR retrotransposons. The two ORFs overlap but are one nucleotide out of frame (+1 frameshift). Most of the approximately 250 copies of TRAS1 elements in the genome were highly conserved in the structure. Chromosomal in situ hybridization showed that TRAS1 elements are clustered at the telomeres of Bombyx chromosomes. A phylogenetic analysis using the amino acid sequence of the reverse transcriptase domain within the pol-like ORF revealed that TRAS1 falls into one lineage with R1, which is a family of non-LTR retrotransposons inserted into the same site within the 28S ribosomal DNA unit in most insects. TRAS1 may have been derived from R1 and changed the target specificity so that TRAS1 inserts into the telomeric repetitive sequence (CCTAA)n. Southern hybridization and Bal 31 exonuclease analyses showed that TRAS1 elements are clustered proximal to the terminal long tract of (CCTAA)n. TRAS1 is a novel family of non-LTR retrotransposons which are inserted into the telomeric repetitive sequences as target sites.


1994 ◽  
Vol 180 (6) ◽  
pp. 2181-2190 ◽  
Author(s):  
E C Gotschlich

A locus involved in the biosynthesis of gonococcal lipooligosaccharide (LOS) has been cloned from gonococcal strain F62. The locus contains five open reading frames. The first and second reading frames are homologous, but not identical, to the fourth and fifth reading frames, respectively. Interposed is an additional reading frame which has distant homology to the Escherichia coli rfaI and rfaI genes, both glucosyl transferases involved in lipopolysaccharide core biosynthesis. The second and fifth reading frames show strong homology to the lex-1 or lic2A gene of Haemophilus influenzae, but do not contain the CAAT repeats found in this gene. Deletions of each of these five genes, of combinations of genes, and of the entire locus were constructed and introduced into parental gonococcal strain F62 by transformation. The LOS phenotypes were then analyzed by SDS-PAGE and reactivity with monoclonal antibodies. Analysis of the gonococcal mutants indicates that four of these genes are the glycosyl transferases that add GalNAc beta 1-->3Gal beta 1-->4GlcNAc beta 1-->3 Gal beta 1--4 to the substrate Glc beta 1-->4Hep--R of the inner core region. The gene with homology to E. coli rfaI/rfaI is involved with the addition of the alpha-linked galactose residue in the biosynthesis of the alternative LOS structure Gal alpha 1-->4Gal beta 1-->4Glc beta 1-->4Hep-->R. Since these genes encode LOS glycosyl transferases they have been named lgtA, lgtB, lgtC, lgtD, and lgtE. The DNA sequence analysis revealed that lgtA, lgtC, and lgtD contained poly-G tracts, which, in strain F62 were, respectively, 17, 10, and 11 bp. Thus, three of the LOS biosynthetic enzymes are potentially susceptible to premature termination by reading frame changes. It is likely that these structural features are responsible for the high-frequency genetic variation of gonococcal LOS.


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