| advances in small isometric multicomponent ssdna viruses infecting plants. | multicomponent ssdna plant viruses were discovered during 1990s. they are associated with bunchy top, yellowing and dwarfing diseases of several economic plants under family musaceae, leguminosae and zingiberaceae. in the current plant virus taxonomy, these viruses are classified under the family nanoviridae containing two genera, nanovirus and babuvirus. the family nanoviridae was created with five members in 2005 and by 2010, it has expanded with four additional members. the viruses are distri ... | 2010 | 23637475 |
| genome diversity and evidence of recombination and reassortment in nanoviruses from europe. | the recent identification of a new nanovirus, pea necrotic yellow dwarf virus, from pea in germany prompted us to survey wild and cultivated legumes for nanovirus infections in several european countries. this led to the identification of two new nanoviruses: black medic leaf roll virus (bmlrv) and pea yellow stunt virus (pysv), each considered a putative new species. the complete genomes of a pysv isolate from austria and three bmlrv isolates from austria, azerbaijan and sweden were sequenced. ... | 2014 | 24515973 |
| application of motif-based tools on evolutionary analysis of multipartite single-stranded dna viruses. | multipartite viruses contain more than one distinctive genome component, and the origin of multipartite viruses has been suggested to evolve from a non-segmented wild-type virus. to explore whether recombination also plays a role in the evolution of the genomes of multipartite viruses, we developed a systematic approach that employs motif-finding tools to detect conserved motifs from divergent genomic regions and applies statistical approaches to select high-confidence motifs. the information th ... | 2013 | 23936517 |
| virus diseases of peas, beans, and faba bean in the mediterranean region. | in the mediterranean region, pea, bean, and faba bean production is affected by around 17 major viruses. these viruses do not have the same ecology and consequently require a variety of different preventive measures to control them. some of these viruses have a narrow host range, such as faba bean necrotic yellows virus (fbnyv), and others, such as alfalfa mosaic virus (amv) and cucumber mosaic virus (cmv), a very wide host range. such features are important when identifying sources of virus ino ... | 2012 | 22682174 |
| the rxl motif of the african cassava mosaic virus rep protein is necessary for rereplication of yeast dna and viral infection in plants. | geminiviruses, single-stranded dna plant viruses, encode a replication-initiator protein (rep) that is indispensable for virus replication. a potential cyclin interaction motif (rxl) in the sequence of african cassava mosaic virus rep may be an alternative link to cell cycle controls to the known interaction with plant homologs of retinoblastoma protein (prbr). mutation of this motif abrogated rereplication in fission yeast induced by expression of wildtype rep suggesting that rep interacts via ... | 2014 | 24999043 |
| two distinct nanovirus species infecting faba bean in morocco. | using monoclonal antibodies raised against a faba bean necrotic yellows virus (fbnyv) isolate from egypt and a faba bean necrotic stunt virus (fbnsv) isolate from ethiopia, a striking serological variability among nanovirus isolates from faba bean in morocco was revealed. to obtain a better understanding of this nanovirus variability in morocco, the entire genomes of two serologically contrasting isolates referred to as mor5 and mor23 were sequenced. the eight circular ssdna components, each ide ... | 2010 | 20069400 |
| epidemiology and integrated management of persistently transmitted aphid-borne viruses of legume and cereal crops in west asia and north africa. | cool-season food legumes (faba bean, lentil, chickpea and pea) and cereals (bread and durum wheat and barley) are the most important and widely cultivated crops in west asia and north africa (wana), where they are the main source of carbohydrates and protein for the majority of the population. persistently transmitted aphid-borne viruses pose a significant limitation to legume and cereal production worldwide. surveys conducted in many countries in wana during the last three decades established t ... | 2009 | 19152820 |
| transcripts encoding the nanovirus master replication initiator proteins are terminally redundant. | the multicomponent single-stranded dna plant nanoviruses encode unique master replication initiator (rep) proteins. we have mapped the 5' and 3' termini of the corresponding polyadenylated mrnas from faba bean necrotic yellows virus (fbnyv) and subterranean clover stunt virus and found that these are terminally redundant by up to about 160 nt. moreover, the origin of viral dna replication is transcribed into rna that is capable of folding into extended secondary structures. other nanovirus genom ... | 2008 | 18198390 |
| arabidopsis thaliana is a host of the legume nanovirus faba bean necrotic yellows virus. | we report infection of arabidopsis thaliana with the legume nanovirus faba bean necrotic yellows virus (fbnyv) by its insect vector aphis craccivora. symptoms of fbnyv infection on a. thaliana include stunting and reduced apical dominance, and are rather mild, compared to the severe necrosis and early plant death induced by the virus in the natural host vicia faba. an inoculation access period of 6h is sufficient to transmit fbnyv to a. thaliana. fbnyv is readily transmitted back from a. thalian ... | 2007 | 17512075 |
| solution structure of the endonuclease domain from the master replication initiator protein of the nanovirus faba bean necrotic yellows virus and comparison with the corresponding geminivirus and circovirus structures. | nanoviruses are a family of plant viruses that possess a genome of multiple circular single-stranded dna (ssdna) components and are strikingly similar in their replication mode to the plant geminiviruses and to the circoviruses that infect birds or mammals. these viruses multiply by rolling circle replication using virus-encoded multifunctional replication initiator proteins (rep proteins) that catalyze the initiation of replication on a double-stranded dna (dsdna) intermediate and the resolutio ... | 2007 | 17472345 |
| infectivity of nanovirus dnas: induction of disease by cloned genome components of faba bean necrotic yellows virus. | circumstantial evidence suggests that the genome of faba bean necrotic yellows virus (fbnyv), a nanovirus, consists of eight distinct, circular, single-stranded dnas, each of about 1 kb and encoding only one protein. here, the use of cloned full-length fbnyv dnas for reproducing fbnyv-like symptoms in vicia faba, the principal natural host of fbnyv, is reported. characteristic symptoms of fbnyv infection were obtained in faba bean plants following biolistic dna delivery or agroinoculation with a ... | 2006 | 16690940 |
| a functional histidine-tagged replication initiator protein: implications for the study of single-stranded dna virus replication in planta. | replication initiation of nanoviruses, plant viruses with a multipartite circular single-stranded dna genome, is triggered by the master rep (m-rep) protein. to enable the study of interactions between m-rep and viral or host factors involved in replication, we designed oligohistidine-tagged variants of the nanovirus faba bean necrotic yellows virus (fbnyv) m-rep protein that allow affinity purification of enzymatically active m-rep from plant tissue. the tagged m-rep protein was able to initiat ... | 2005 | 15956586 |
| birth-and-death evolution of protein-coding regions and concerted evolution of non-coding regions in the multi-component genomes of nanoviruses. | genomes of the four plant viruses of the genus nanovirus consist of multiple circular single-stranded dna components, each of which encodes a single protein. protein phylogenies supported the hypothesis that faba bean necrotic yellows virus (fbnyv) and milk vetch disease virus (mdv) are sister taxa; that subterranean clover stunt virus (scsv) branched next; and that banana bunchy top virus (bbtv) is an outgroup to the three other species. the phylogeny of replication (rep) proteins indicate that ... | 2004 | 14715221 |
| in planta protein-protein interactions assessed using a nanovirus-based replication and expression system. | the multipartite genome of the nanovirus faba bean necrotic yellows virus, which consists of one gene on each dna component, was exploited to construct a series of virus-based episomal vectors designed for transient replication and gene expression in plants. this nanovirus based expression system yields high levels of protein which allows isolation of recombinant protein and protein complexes from plant tissues. as examples, we demonstrated in planta interaction between the nanovirus f-box prote ... | 2002 | 12220267 |
| the master rep concept in nanovirus replication: identification of missing genome components and potential for natural genetic reassortment. | faba bean necrotic yellows virus (fbynv), milk vetch dwarf virus (mdv), and subterranean clover stunt virus (scsv) are nanoviruses that infect leguminous plants. from mdv- and scsv-infected tissue we identified viral dnas that encode a replication initiator protein (rep), essential for replication of the multiple circular single-stranded dnas of these viruses. these previously undescribed rep proteins of mdv and scsv are strikingly similar in sequence and functionally equivalent to the master re ... | 2000 | 10936099 |
| clink, a nanovirus-encoded protein, binds both prb and skp1. | clink, a 20-kda protein of faba bean necrotic yellows virus, a single-stranded dna plant virus, interacts with prb family members and a skp1 homologue from medicago sativa. an lxcxe motif and an f-box of clink mediate the interactions with the respective proteins. the capacity of clink to bind prb correlates with its ability to stimulate viral replication. interaction of a single protein with the cell cycle regulator prb and skp1, a constituent of the ubiquitin-protein turnover pathway, appears ... | 2000 | 10708410 |
| a single rep protein initiates replication of multiple genome components of faba bean necrotic yellows virus, a single-stranded dna virus of plants. | faba bean necrotic yellows virus (fbnyv) belongs to the nanoviruses, plant viruses whose genome consists of multiple circular single-stranded dna components. eleven distinct dnas, 5 of which encode different replication initiator (rep) proteins, have been identified in two fbnyv isolates. origin-specific dna cleavage and nucleotidyl transfer activities were shown for rep1 and rep2 proteins in vitro, and their essential tyrosine residues that catalyze these reactions were identified by site-direc ... | 1999 | 10559333 |
| faba bean necrotic yellows virus (genus nanovirus) requires a helper factor for its aphid transmission. | purified faba bean necrotic yellows virus (fbnyv; genus nanovirus) alone is not transmissible by its aphid vector, acyrthosiphon pisum, regardless of whether it is acquired from artificial diets or directly microinjected into the aphid's hemocoel. the purified virus contains all of the genetic information required for its infection cycle as it readily replicated in cowpea protoplasts and systemically infected vicia faba seedlings that were biolistically inoculated using gold particles coated wit ... | 1999 | 10489354 |
| sequences of ten circular ssdna components associated with the milk vetch dwarf virus genome. | milk vetch dwarf virus (mdv) is a member of the proposed genus nanovirus, and its genome is composed of multiple, circular ssdna components of about 1 kb. we have cloned and sequenced ten ssdna components and designated them mdv-c1 to c10. each dna component contains one potential major open reading frame, and contains a putative stem-loop structure in the non-coding region. notably, four components (c1, c2, c3 and c10) encode distinct replication-associated (rep) proteins of 33 kda, which show ... | 1998 | 9880029 |
| ten distinct circular ssdna components, four of which encode putative replication-associated proteins, are associated with the faba bean necrotic yellows virus genome. | four further circular ssdna components (c7-c10), about 1 kb in size and structurally similar to the previously described components (c1-c6) found associated with a syrian (sy) isolate of faba bean necrotic yellows virus (fbnyv), have been identified. similar to c1 and c2, two of the new components (c7 and c9) encode putative replication-associated (rep) proteins of 33.2 and 32.7 kda, respectively, the former of which is 90% identical to the c10 rep protein of milk vetch dwarf virus (mdv). c8 enc ... | 1998 | 9880028 |
| psittacine beak and feather disease virus nucleotide sequence analysis and its relationship to porcine circovirus, plant circoviruses, and chicken anaemia virus. | cloning and sequencing of the circular, single-stranded dna of one isolate of psittacine beak and feather disease virus (bfdv) demonstrate a genome composed of a circular molecule of 1993 nucleotide bases. an analysis of the assembled replicative form demonstrated seven open reading frames (orfs) (three in the virion strand and four in the complementary strand), potentially encoding seven viral proteins of >8.7 kda. high amino acid sequence similarity was demonstrated between a potential 33.3-kd ... | 1998 | 9791035 |
| analysis of six dna components of the faba bean necrotic yellows virus genome and their structural affinity to related plant virus genomes. | faba bean necrotic yellows virus (fbnyv) has a multicomponent circular ssdna genome. in addition to a previously described genome component (c1) coding for a replicase-associated protein (rep), five further components (c2 to c6) have now been identified. each of the six components is about 1 kb in size, contains one major open reading frame (orf) in the virion sense with a tata box and polyadenylation signal, and has a noncoding region containing a highly conserved sequence possibly forming a st ... | 1997 | 9217049 |
| sequence analysis of a faba bean necrotic yellows virus dna component containing a putative replicase gene. | faba bean necrotic yellows virus (fbnyv) has a circular ssdna genome possibly consisting of several components of about 1 kb each. the complete nucleotide sequence of one component of fbnyv (fbnyv dna 1) containing a putative replicase gene is presented. this component consists of 1002 nucleotides and, in the virion orientation, contains one large open reading frame (orf1) potentially encoding a 32.3 kda replicase with the ntp-binding motif ggegks. no obvious functions could be assigned to two s ... | 1995 | 7844570 |
| the genome organization of banana bunchy top virus: analysis of six ssdna components. | we have cloned, sequenced and analysed an additional five circular ssdna components of banana bunchy top virus (bbtv) which we have called components 2, 3, 4, 5 and 6. these components were present in all bbtv infections tested. four of these components (components 3, 4, 5 and 6) had one large open reading frame (orf) in the virion sense located 3' of a stem-loop structure. each orf had a potential tata box and one or two potential polyadenylation signals associated with it and each polyadenylat ... | 1995 | 7782775 |