Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.48 (transcriptase)
 9,479 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study reports the molecular characterization of a flexuous rod-shaped mycovirus, Botrytis virus X (BVX), infecting the plant-pathogenic fungus, Botrytis cinerea. BVX contains a ssRNA genome of 6966 nucleotides, and a poly(A) tract at or very near the 3' terminus. Computer analysis of the genomic cDNA sequence of BVX revealed five potential open reading frames (ORFs). ORF1 showed significant amino acid sequence identity to the replicase proteins of plant 'potex-like' viruses, including 73% identity to the RNA-dependent RNA polymerase (RdRp) region of the allexivirus, garlic virus A (GarV-A). The C-terminal region of ORF3 shared amino acid homology with plant 'potex-like' coat proteins. The remaining ORFs did not reveal significant homology with known protein sequences. BVX differs substantially from Botrytis virus F (BVF), another flexuous rod-shaped mycovirus characterized from the same B. Cinerea isolate. It is proposed that the mycovirus BVX belongs to a new, as yet unassigned genus in the plant 'potex-like' virus group, distinct from BVF.
 ...
PMID:Genome characterization of a flexuous rod-shaped mycovirus, Botrytis virus X, reveals high amino acid identity to genes from plant 'potex-like' viruses. 1617 41

A total of 154 partial nucleotide sequences within the Banana mild mosaic virus (BanMMV) ORF1, which encodes the viral RNA-dependent RNA polymerase (RdRp), was obtained from 68 distinct infected banana accessions originating from various locations worldwide. The 310 nt sequences displayed a high level of variability with a mean pairwise nucleotide sequence divergence level of 20.4 %. This situation resulted essentially from a high rate of synonymous mutations. A similar analysis was performed for a limited selection of 10 banana accessions (30 sequences) on the region comprising approximately the last 310 nt of the BanMMV genome. This region corresponds to the 3' end of ORF5, which encodes the coat protein (234 nt), and to the 3' non-coding region. This analysis confirmed the high level of diversity observed in the RdRp dataset, characterized by a high level of synonymous mutations. Analysis of intra-host diversity indicated the existence of two distinct situations, with some plants containing only closely related sequence variants, whereas others contained widely divergent isolates. Analyses indicated that BanMMV genetic diversity is not structured by the geographical origin of the infected Musa accessions or by their genotype. This situation may be, in part, explained by the exchange of banana germplasm between different parts of the world and also by plant-to-plant transfer of virus isolates, the evidence for which is, for the first time, provided by this study.
 ...
PMID:High genetic variability and evidence for plant-to-plant transfer of Banana mild mosaic virus. 1622 42

The complete nucleotide sequence of the genomic RNA of a marine fungoid protist-infecting virus (Schizochytrium single-stranded RNA virus; SssRNAV) has been determined. The viral RNA is single-stranded with a positive sense and is 9,018 nt in length [excluding the 3' poly(A) tail]. It contains two long open reading frames (ORFs), which are separated by an intergenic region of 92 nt. The 5' ORF (ORF1) is preceded by an untranslated leader sequence of 554 nt. The 3' large ORF (ORF2) and an additional ORF (ORF3) overlap ORF2 by 431 nt and are followed by an untranslated region of 70 nt [excluding the 3' poly(A) tail]. The deduced amino acid sequences of ORF1 and ORF2 products show similarity to non-structural and structural proteins of dicistroviruses, respectively. However, Northern blot analysis suggests that SssRNAV synthesizes subgenomic RNAs to translate ORF2 and ORF3, showing that the translation mechanism of downstream ORFs is distinct from that of dicistroviruses. Furthermore, although considerable similarities were detected by using a blast genome database search, phylogenetic analysis based on both the nucleotide and amino acid sequences of the putative RNA-dependent RNA polymerase (RdRp) and the RNA helicase suggests that SssRNAV is phylogenetically distinct from other virus families. Therefore, it is concluded that SssRNAV is not a member of any currently defined virus family and belongs to a novel, unrecognized virus group.
 ...
PMID:Complete nucleotide sequence and genome organization of a single-stranded RNA virus infecting the marine fungoid protist Schizochytrium sp. 1647 96

Pediatric gastroenteritis is a major cause of childhood morbidity and mortality worldwide, especially in developing countries. It has been increasingly recognised that human caliciviruses (HuCV), comprising noroviruses (NoV), and sapoviruses (SaV), are important in both outbreak and non-outbreak settings. This study aimed to characterise caliciviruses detected in the faeces of hospitalized children and children in the community in India. This study examined 350 faecal samples from children presenting to the hospital with acute gastroenteritis and 673 samples collected from children in the community, 500 from children with diarrhea, and 173 samples from children without diarrhea. Strain characterisation was performed by reverse transcription-polymerase chain reaction (RT-PCR) and partial sequencing of the gene encoding the RNA-dependent RNA polymerase (RdRp) and/or a region spanning the open reading frames (ORFs) 1 and 2 (ORF1/ORF2) junction. A total of 68 of 350 specimens (19.4%) from hospitalized children were positive, and SaV and NoV accounted for 5.1 and 15.1% of the infections, respectively. Mixed infections of HuCVs with other enteric pathogens were seen in 9.4% of the total children tested. Sixty-eight out of 673 (10.1%) samples collected from children in the community were positive for caliciviruses, and SaV and NoV accounted for 3.4 and 6.6% of the infections. In the community cohort 55/500 (11%) and 13/173 (7.5%) were from symptomatic and asymptomatic children, respectively, and SaVs accounted for 17/500 (3.4%) and NoVs for 38/500 (7.6%) of the symptomatic infections. This is the first report of genotyping of circulating caliciviruses in both hospital and community in India and has increased the evidence for the role of these viruses in pediatric gastroenteritis in India.
 ...
PMID:Human caliciviruses in symptomatic and asymptomatic infections in children in Vellore, South India. 1738 96

Fusarium graminearum causes a serious scab disease of small grains in Korea. The nucleotide sequence of the genomic RNA of a double-stranded RNA (dsRNA) virus, Fusarium graminearum virus-DK21 (FgV-DK21), from F. graminearum strain DK21, which is associated with hypovirulence in F. graminearum, was determined and compared to the genome sequences of other mycoviruses, including Cryponectria hypoviruses. The FgV-DK21 dsRNA consists of 6,621 [corrected] nucleotides, excluding the 3'-terminal poly(A) tail. The viral genome has 53- and 46-nucleotide 5' and 3' untranslated regions (UTRs), respectively, and four [corrected] putative open reading frames. A phylogenetic analysis of the deduced amino acid sequence of ORF1, which encodes a putative RNA-dependent RNA polymerase, and those of other mycoviruses revealed that this organism forms a distinct virus clade with other hypoviruses, and is more distantly related to other mycoviruses (3.8 to 24.0% identity). However, pairwise sequence comparisons of the nucleotide and deduced amino acid sequences of ORFs 2 through 4 [corrected] revealed no close relationships to other protein sequences currently available in GenBank. Analyses of RNA accumulation by Northern blot and primer extension indicated that these putative gene products are expressed from at least two different subgenomic RNAs (sgRNAs), in contrast to the cases in other hypoviruses. This study suggests the existence of a new, as yet unassigned, genus of mycoviruses that exhibits a potex-like genome organization and sgRNA accumulation.
 ...
PMID:Molecular characterization of a dsRNA mycovirus, Fusarium graminearum virus-DK21, which is phylogenetically related to hypoviruses but has a genome organization and gene expression strategy resembling those of plant potex-like viruses. 1764 4

Viruses in garlic plants (Allium sativum L.) have accumulated and evolved over generations, resulting in serious consequences for the garlic trade around the world. These viral epidemics are also known to be caused by aphids and eriophyid mites (Aceria tulipae) carrying Potyviruses, Carlaviruses, and Allexiviruses. However, little is known about viral epidemics in garlic plants caused by eriophyid mites. Therefore, this study investigated the infection of garlic plants with Allexiviruses by eriophyid mites. When healthy garlic plants were cocultured with eriophyid mites, the leaves of the garlic plants developed yellow mosaic strips and became distorted. In extracts from the eriophyid mites, Allexiviruses were observed using immunosorbent electron microscopy (ISEM). From an immunoblot analysis, coat proteins against an Allexivirus garlic-virus antiserum were clearly identified in purified extracts from collected viral-infected garlic plants, eriophyid mites, and garlic plants infected by eriophyid mites. A new strain of GarV-B was isolated and named GarV-B Korea isolate 1 (GarV-B1). The ORF1 and ORF2 in GarV-B1 contained a typical viral helicase, RNA-directed RNA polymerase (RdRp), and triple gene block protein (TGBp) for viral movement between cells. The newly identified GarV-B1 was phylogenetically grouped with GarV-C and GarV-X in the Allexivirus genus. All the results in this study demonstrated that eriophyid mites are a transmitter insect species for Allexiviruses.
 ...
PMID:Allexivirus transmitted by eriophyid mites in garlic plants. 1809 68

The complete genomic nucleotide sequence of an Indian isolate of Lily symptomless virus (LSV) was determined by sequencing 11 overlapping cDNA fragments of different sizes. The genome consisted of 8,394 nucleotides, excluding the poly (A) tail and contained six open reading frames (ORFs) coding protein for ORF1 220 kDa [1,948 amino acid (aa)], ORF2 25 kDa (228 aa), ORF3 12 kDa (106 aa), ORF4 7 kDa (64 aa), ORF5 32 kDa (291 aa) and ORF6 16 kDa (140 aa) from 5' to 3' end. Sequence was analyzed with other previously characterized full genomes of LSV. Phylogenetic analysis on the basis of RNA-dependent RNA polymerase (RdRp), Triple gene block proteins (TGB's), Coat protein (CP), and ORF6 (16 kDa protein) amino acid sequence revealed that Indian isolate is closely related to The Netherlands Isolate (AJ564638). The overall genome of the present LSV isolate shares 97-98% nucleotide sequence homology with the previously characterized isolates. The phylogenetic analysis, sequence alignment studies, and recombination detection program (RDP3) analysis provided evidence for the occurrence of recombination between the present isolate (AM422452) as major parent and The Netherlands Isolate (AJ564638) and Chinese isolate (AM263208) as minor parents in two different independent recombination events. Based on the recombination analysis, it is suggested that the 3' end of the present isolate is involved in recombination with Chinese isolate (AM263208) and gave rise to the Korean isolate. To the best of our knowledge, this is the first report of complete nucleotide sequence from India and also the first evidence of homologous recombination in LSV.
 ...
PMID:Recombination and phylogeographical analysis of Lily symptomless virus. 1820 6

Norovirus (NoV) is a major etiological agent of acute gastroenteritis outbreaks worldwide. A total of 314 fecal specimens collected from patients of 39 NoV gastroenteritis outbreaks in Hiroshima Prefecture, Japan, between December 2001 and April 2006 were tested for the occurrence of recombinant NoVs. Sixteen genotypes (GI/1, GI/2, GI/4, GI/7, GI/8, GI/11, GI/14, GII/2, GII/3, GII/4, GII/5, GII/6, GII/8, GII/12, GII/14, and GII/untypeable) were detected in the 39 outbreaks based on capsid sequences and GII/4 was predominant recently. Twelve strains detected in 11 (28.2%) of the 39 outbreaks were suspected to be recombinants by using Simplot and Recco analyses and five recombinant genotypes, GII/4-GII/12 (five strains), GIIb-GII/3 (four strains), GII/4-GII/2 (one strain), GII/4-GII/14 (one strain), and GI/2-GI/8 (one strain), were identified based on RNA-dependent RNA polymerase and capsid sequences. None of the strains genotyped as GII/4 based on the capsid sequence was identified as a recombinant. The putative recombination points in the recombinant strains were placed either upstream or downstream of the open reading frame (ORF) 1 and ORF2 overlap. The present study indicates the following: (a) recombination among ORFs is common in nature, (b) the involvement of recombinant NoVs in gastroenteritis outbreaks is extensive even in a local area such as Hiroshima Prefecture, Japan, and (c) the conserved region (ORF1 and ORF2 overlap) has a meaningful function against the recombination event.
 ...
PMID:Recombinant norovirus implicated in gastroenteritis outbreaks in Hiroshima Prefecture, Japan. 1836 Sep 6

Whether animals may act as reservoirs for human caliciviruses is unclear. By sequence analysis of a short fragment of the RNA-dependent RNA polymerase (RdRp) region, porcine sapovirus (SaV) strains that genetically resemble human SaVs have been detected in piglets, but more-informative sequences (capsid gene) were not available for a precise characterization. In this study, the 3' terminus (the 3' end of open reading frame 1 [ORF1], including the polymerase complex and the complete capsid; ORF2; and the 3' untranslated region) of one such human SaV-like strain, 43/06-18p3/2006/It, was determined, revealing that these viruses are more related genetically to human (47.4 to 54.9% amino acid identity) than to animal (35.2 to 44.7% amino acid identity) SaVs in the capsid gene. In addition, the recombination-prone RdRp-capsid junction region was highly conserved with those of human SaVs of genogroup GI. The presence of porcine viruses similar to human SaVs is a significant finding because of the potential for zoonotic infections or generation of porcine/human recombinants.
 ...
PMID:Identification of a porcine calicivirus related genetically to human sapoviruses. 1841 56

ABSTRACT Grapevine rupestris stem pitting (RSP) is a graft-transmissible disease of unknown etiology. We have characterized a virus associated with this disease. The entire genomic sequence (GenBank accession number AF026278) consisted of 8,725 nucleotides excluding a poly(A) tail. Six open reading frames (ORF) were found. ORF1 potentially encodes a polypeptide with a methyltransferase domain, a papain-like proteinase domain, a helicase domain, and a RNA-dependent RNA polymerase domain; ORF2, ORF3, and ORF4 compose a triple-gene block; ORF5 encodes a coat protein; and ORF6 is located near the 3' end with unknown function. Sequence analysis indicated that the virus is most similar to apple stem-pitting virus and may be allied with the carla- and potexviruses and grouped with other viruses that infect woody hosts. A specific reverse-transcription polymerase chain reaction (RT-PCR)-based detection method was developed. Among 62 grapevine sources known to be infected with rupestris stem-pitting disease, 60 sources tested positive by RT-PCR. Among 43 healthy vines tested, all were negative. The name grapevine rupestris stem-pitting-associated virus is proposed.
 ...
PMID:Nucleotide sequence and rt-PCR detection of a virus associated with grapevine rupestris stem-pitting disease. 1894 59


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>