| phylogeny of the genus flavivirus. | we undertook a comprehensive phylogenetic study to establish the genetic relationship among the viruses of the genus flavivirus and to compare the classification based on molecular phylogeny with the existing serologic method. by using a combination of quantitative definitions (bootstrap support level and the pairwise nucleotide sequence identity), the viruses could be classified into clusters, clades, and species. our phylogenetic study revealed for the first time that from the putative ancesto ... | 1998 | 9420202 |
| phylogeny of the genus flavivirus using complete coding sequences of arthropod-borne viruses and viruses with no known vector. | attempts to define the evolutionary relationships and origins of viruses in the genus flavivirus are hampered by the lack of genetic information particularly amongst the non-vectored flaviviruses. using a novel protocol for sequence determination, the first complete coding sequence of st louis encephalitis virus and those of two representative non-vectored flaviviruses, rio bravo (isolated from bat) and apoi (isolated from rodent), are reported. the encoded polyproteins of rio bravo and apoi vir ... | 2000 | 10675416 |
| biophysical characterization and vector-specific antagonist activity of domain iii of the tick-borne flavivirus envelope protein. | the molecular determinants responsible for flavivirus host cell binding and tissue tropism are largely unknown, although domain iii of the envelope protein has been implicated in these functions. we examined the solution properties and antagonist activity of langat virus domain iii. our results suggest that domain iii adopts a stably folded structure that can mediate binding of tick-borne flaviviruses but not mosquito-borne flaviviruses to their target cells. three clusters of phylogenetically c ... | 2001 | 11264392 |
| characterization of a siberian virus isolated from a patient with progressive chronic tick-borne encephalitis. | a strain of tick-borne encephalitis virus designated zausaev (za) was isolated in siberia from a patient who died of a progressive (2-year) form of tick-borne encephalitis 10 years after being bitten by a tick. the complete genomic sequence of this virus was determined, and an attempt was made to correlate the sequence with the biological characteristics of the virus. phylogenetic analysis demonstrated that this virus belongs to the siberian subtype of tick-borne encephalitis virus. comparison o ... | 2003 | 12477807 |
| exchanging the yellow fever virus envelope proteins with modoc virus prm and e proteins results in a chimeric virus that is neuroinvasive in scid mice. | a chimeric flavivirus infectious cdna was constructed by exchanging the premembrane (prm) and envelope (e) genes of the yellow fever virus vaccine strain 17d (yf17d) with the corresponding genes of modoc virus (mod). this latter virus belongs to the cluster of the "not-known vector" flaviviruses and is, unlike yf17d, neuroinvasive in scid mice. replication of in vitro-transcribed rna from this chimeric flavivirus was shown by [(3)h]uridine labeling and rna analysis. expression of the mod prm and ... | 2004 | 15220415 |
| low diversity of alkhurma hemorrhagic fever virus, saudi arabia, 1994-1999. | alkhurma hemorrhagic fever virus (genus flavivirus, ahfv) was recently identified as the agent of a viral hemorrhagic fever in saudi arabia and characterized serologically and genetically as a variant genotype of kyasanur forest disease virus (kfdv). since viral diagnosis and vaccine development may be hindered by genetic diversity, this study was intended to address ahfv genetic heterogeneity. eleven strains isolated from hospitalized patients from 1994 to 1999 in saudi arabia were sequenced in ... | 2005 | 15890119 |
| the modeled structure of the rna dependent rna polymerase of gbv-c virus suggests a role for motif e in flaviviridae rna polymerases. | the flaviviridae virus family includes major human and animal pathogens. the rna dependent rna polymerase (rdrp) plays a central role in the replication process, and thus is a validated target for antiviral drugs. despite the increasing structural and enzymatic characterization of viral rdrps, detailed molecular replication mechanisms remain unclear. the hepatitis c virus (hcv) is a major human pathogen difficult to study in cultured cells. the bovine viral diarrhea virus (bvdv) is often used as ... | 2005 | 16225688 |
| structural bases for substrate recognition and activity in meaban virus nucleoside-2'-o-methyltransferase. | viral methyltransferases are involved in the mrna capping process, resulting in the transfer of a methyl group from s-adenosyl-l-methionine to capped rna. two groups of methyltransferases (mtases) are known: (guanine-n7)-methyltransferases (n7mtases), adding a methyl group onto the n7 atom of guanine, and (nucleoside-2'-o-)-methyltransferases (2'omtases), adding a methyl group to a ribose hydroxyl. we have expressed and purified two constructs of meaban virus (mv; genus flavivirus) ns5 protein m ... | 2007 | 17473012 |
| a new flavivirus and a new vector: characterization of a novel flavivirus isolated from uranotaenia mosquitoes from a tropical rain forest. | a novel flavivirus was isolated from uranotaenia mashonaensis, a mosquito genus not previously known to harbor flaviviruses. mosquitoes were caught in the primary rain forest of the taï national park, côte d'ivoire. the novel virus, termed nounané virus (nouv), seemed to grow only on c6/36 insect cells and not on vertebrate cells. typical enveloped flavivirus-like particles of 60 to 65 nm in diameter were detected by electron microscopy in the cell culture supernatant of infected cells. the full ... | 2009 | 19224998 |
| characterization of a novel flavivirus from mosquitoes in northern europe that is related to mosquito-borne flaviviruses of the tropics. | a novel flavivirus was isolated from mosquitoes in finland, representing the first mosquito-borne flavivirus from northern europe. the isolate, designated lammi virus (lamv), was antigenically cross-reactive with other flaviviruses and exhibited typical flavivirus morphology as determined by electron microscopy. the genomic sequence of lamv was highly divergent from the recognized flaviviruses, and yet the polyprotein properties resembled those of mosquito-borne flaviviruses. phylogenetic analys ... | 2009 | 19570865 |
| virus-host coevolution: common patterns of nucleotide motif usage in flaviviridae and their hosts. | virus-host biological interaction is a continuous coevolutionary process involving both host immune system and viral escape mechanisms. flaviviridae family is composed of fast evolving rna viruses that infects vertebrate (mammals and birds) and/or invertebrate (ticks and mosquitoes) organisms. these host groups are very distinct life forms separated by a long evolutionary time, so lineage-specific anti-viral mechanisms are likely to have evolved. flaviviridae viruses which infect a single host l ... | 2009 | 19617912 |
| structure of yellow fever virus envelope protein domain iii. | the structure of recombinant domain iii of the envelope protein (red3) of yellow fever virus (yfv), containing the major neutralization site, was determined using nmr spectroscopy. the amino acid sequence and structure of the yfv-red3 shows differences from ed3s of other mosquito-borne flaviviruses; in particular, the partially surface-exposed bc loop where methionine-304 and valine-324 were identified as being critical for the structure of the loop. variations in the structure and surface chemi ... | 2009 | 19818466 |
| structure and functionality in flavivirus ns-proteins: perspectives for drug design. | flaviviridae are small enveloped viruses hosting a positive-sense single-stranded rna genome. besides yellow fever virus, a landmark case in the history of virology, members of the flavivirus genus, such as west nile virus and dengue virus, are increasingly gaining attention due to their re-emergence and incidence in different areas of the world. additional environmental and demographic considerations suggest that novel or known flaviviruses will continue to emerge in the future. nevertheless, u ... | 2010 | 19945487 |
| structural and functional analyses of a conserved hydrophobic pocket of flavivirus methyltransferase. | the flavivirus methyltransferase (mtase) sequentially methylates the n7 and 2'-o positions of the viral rna cap (gpppa-rna → m(7)gpppa-rna → m(7)gpppam-rna), using s-adenosyl-l-methionine (adomet) as a methyl donor. we report here that sinefungin (sin), an adomet analog, inhibits several flaviviruses through suppression of viral mtase. the crystal structure of west nile virus mtase in complex with sin inhibitor at 2.0-å resolution revealed a flavivirus-conserved hydrophobic pocket located next t ... | 2010 | 20685660 |
| evidence of simultaneous circulation of west nile and usutu viruses in mosquitoes sampled in emilia-romagna region (italy) in 2009. | in recent years human diseases due to mosquito-borne viruses were increasingly reported in emilia-romagna region (italy), from the chikungunya virus in 2007 to the west nile virus (wnv) in 2008. an extensive entomological survey was performed in 2009 to establish the presence and distribution of mosquito arboviruses in this region, with particular reference to flaviviruses. | 2010 | 21179462 |
| distribution and phylogenetic comparisons of a novel mosquito flavivirus sequence present in culex tarsalis mosquitoes from western canada with viruses isolated in california and colorado. | in a previous study, a new flavivirus genome sequence was identified in culex tarsalis mosquitoes obtained in alberta, canada and was shown to be genetically related to but distinct from members of the insect-specific flaviviruses. nonstructural protein 5-encoding sequences amplified from cx. tarsalis pools from western canada have shown a high similarity to genome sequences of novel flaviviruses isolated from mosquitoes in california and colorado. despite wide distribution of this virus, design ... | 2011 | 21734143 |
| Tembusu virus in ducks, china. | In China in 2010, a disease outbreak in egg-laying ducks was associated with a flavivirus. The virus was isolated and partially sequenced. The isolate exhibited 87%-91% identity with strains of Tembusu virus, a mosquito-borne flavivirus of the Ntaya virus group. These findings demonstrate emergence of Tembusu virus in ducks. | 2011 | 22000358 |
| biological transmission of arboviruses: reexamination of and new insights into components, mechanisms, and unique traits as well as their evolutionary trends. | among animal viruses, arboviruses are unique in that they depend on arthropod vectors for transmission. field research and laboratory investigations related to the three components of this unique mode of transmission, virus, vector, and vertebrate host, have produced an enormous amount of valuable information that may be found in numerous publications. however, despite many reviews on specific viruses, diseases, or interests, a systematic approach to organizing the available information on all f ... | 0 | 16223950 |
| noncoding subgenomic flavivirus rna: multiple functions in west nile virus pathogenesis and modulation of host responses. | flaviviruses are a large group of positive strand rna viruses transmitted by arthropods that include many human pathogens such as west nile virus (wnv), japanese encephalitis virus (jev), yellow fever virus, dengue virus, and tick-borne encephalitis virus. all members in this genus tested so far are shown to produce a unique subgenomic flavivirus rna (sfrna) derived from the 3' untranslated region (utr). sfrna is a product of incomplete degradation of genomic rna by the cell 5'-3' exoribonucleas ... | 2014 | 24473339 |
| a glance at subgenomic flavivirus rnas and micrornas in flavivirus infections. | the family flaviviridae comprises a wide variety of viruses that are distributed worldwide, some of which are associated with high rates of morbidity and mortality. there are neither vaccines nor antivirals for most flavivirus infections, reinforcing the importance of research on different aspects of the viral life cycle. during infection, cytoplasmic accumulation of rna fragments mainly originating from the 3' utrs, which have been designated subgenomic flavivirus rnas (sfrnas), has been detect ... | 2016 | 27233361 |
| ecuador paraiso escondido virus, a new flavivirus isolated from new world sand flies in ecuador, is the first representative of a novel clade in the genus flavivirus. | a new flavivirus, ecuador paraiso escondido virus (epev), named after the village where it was discovered, was isolated from sand flies (psathyromyia abonnenci, formerly lutzomyia abonnenci) that are unique to the new world. this represents the first sand fly-borne flavivirus identified in the new world. epev exhibited a typical flavivirus genome organization. nevertheless, the maximum pairwise amino acid sequence identity with currently recognized flaviviruses was 52.8%. phylogenetic analysis o ... | 2015 | 26355096 |
| new insights into flavivirus evolution, taxonomy and biogeographic history, extended by analysis of canonical and alternative coding sequences. | to generate the most diverse phylogenetic dataset for the flaviviruses to date, we determined the genomic sequences and phylogenetic relationships of 14 flaviviruses, of which 10 are primarily associated with culex spp. mosquitoes. we analyze these data, in conjunction with a comprehensive collection of flavivirus genomes, to characterize flavivirus evolutionary and biogeographic history in unprecedented detail and breadth. based on the presumed introduction of yellow fever virus into the americ ... | 2015 | 25719412 |
| identification of a flavivirus sequence in a marine arthropod. | phylogenetic analysis has yet to uncover the early origins of flaviviruses. in this study, i mined a database of expressed sequence tags in order to discover novel flavivirus sequences. flavivirus sequences were identified in a pool of mrna extracted from the sea spider endeis spinosa (pycnogonida, pantopoda). reconstruction of the translated sequences and blast analysis matched the sequence to the flavivirus ns5 gene. additional sequences corresponding to envelope and the ns5 mtase domain were ... | 2015 | 26717191 |
| usutu virus: an emerging flavivirus in europe. | usutu virus (usuv) is an african mosquito-borne flavivirus belonging to the japanese encephalitis virus serocomplex. usuv is closely related to murray valley encephalitis virus, japanese encephalitis virus, and west nile virus. usuv was discovered in south africa in 1959. in europe, the first true demonstration of circulation of usuv was reported in austria in 2001 with a significant die-off of eurasian blackbirds. in the subsequent years, usuv expanded to neighboring countries, including italy, ... | 2015 | 25606971 |
| characterization of a novel insect-specific flavivirus from brazil: potential for inhibition of infection of arthropod cells with medically important flaviviruses. | in the past decade, there has been an upsurge in the number of newly described insect-specific flaviviruses isolated pan-globally. we recently described the isolation of a novel flavivirus (tentatively designated 'nhumirim virus'; nhuv) that represents an example of a unique subset of apparently insect-specific viruses that phylogenetically affiliate with dual-host mosquito-borne flaviviruses despite appearing to be limited to replication in mosquito cells. we characterized the in vitro growth p ... | 2014 | 25146007 |
| rapid evolutionary dynamics of structural disorder as a potential driving force for biological divergence in flaviviruses. | protein structure is commonly regarded to be conserved and to dictate function. most proteins rely on conformational flexibility to some degree. are regions that convey conformational flexibility conserved over evolutionary time? can changes in conformational flexibility alter protein function? here, the evolutionary dynamics of structurally ordered and disordered (flexible) regions are investigated genome-wide in flaviviruses, revealing that the amount and location of structural disorder fluctu ... | 0 | 23418179 |
| ilheus virus isolation in the pantanal, west-central brazil. | the wetlands of the brazilian pantanal host large concentrations of diverse wildlife species and hematophagous arthropods, conditions that favor the circulation of zoonotic arboviruses. a recent study from the nhecolândia sub-region of pantanal reported serological evidence of various flaviviruses, including west nile virus and ilheus virus (ilhv). according to the age of seropositive horses, at least three flaviviruses, including ilhv, circulated in the brazilian pantanal between 2005 and 2009. ... | 2013 | 23875051 |
| flaviviruses in europe: complex circulation patterns and their consequences for the diagnosis and control of west nile disease. | in europe, many flaviviruses are endemic (west nile, usutu, tick-borne encephalitis viruses) or occasionally imported (dengue, yellow fever viruses). due to the temporal and geographical co-circulation of flaviviruses in europe, flavivirus differentiation by diagnostic tests is crucial in the adaptation of surveillance and control efforts. serological diagnosis of flavivirus infections is complicated by the antigenic similarities among the flavivirus genus. indeed, most flavivirus antibodies are ... | 2013 | 24225644 |
| flavidb: a data mining system for knowledge discovery in flaviviruses with direct applications in immunology and vaccinology. | the flavivirus genus is unusually large, comprising more than 70 species, of which more than half are known human pathogens. it includes a set of clinically relevant infectious agents such as dengue, west nile, yellow fever, and japanese encephalitis viruses. although these pathogens have been studied extensively, safe and efficient vaccines lack for the majority of the flaviviruses. | 0 | 25544857 |
| genetic characterization of an insect-specific flavivirus isolated from culex theileri mosquitoes collected in southern portugal. | we describe the full genetic characterization of an insect-specific flavivirus (isf) from culex theileri (theobald) mosquitoes collected in portugal. this represents the first isolation and full characterization of an isf from portuguese mosquitoes. the virus, designated ctfv, for culex theileri flavivirus, was isolated in the c6/36 stegomyia albopicta (=aedes albopictus) cell line, and failed to replicate in vertebrate (vero) cells in common with other isfs. the ctfv genome encodes a single pol ... | 2012 | 22579596 |
| characterisation of divergent flavivirus ns3 and ns5 protein sequences detected in rhipicephalus microplus ticks from brazil. | transcripts similar to those that encode the nonstructural (ns) proteins ns3 and ns5 from flaviviruses were found in a salivary gland (sg) complementary dna (cdna) library from the cattle tick rhipicephalus microplus. tick extracts were cultured with cells to enable the isolation of viruses capable of replicating in cultured invertebrate and vertebrate cells. deep sequencing of the viral rna isolated from culture supernatants provided the complete coding sequences for the ns3 and ns5 proteins an ... | 2013 | 24626302 |
| detection of quang binh virus from mosquitoes in china. | flaviviruses present a wide range of genetic diversity and exhibit diverse host relationships. mosquito-borne flaviviruses have recently been isolated and characterized worldwide. yunnan province of china is one of the richest areas of species diversity and is the center of multi-species evolution in mainland asia, which supports the circulation of numerous arthropod-borne viruses (arboviruses). in a screening program of arboviruses, mosquitoes were collected during the mosquito activity season ... | 2014 | 24342141 |
| analysis of synonymous codon usage bias in flaviviridae virus. | flaviviridae viruses are single-stranded, positive-sense rna viruses, which threat human constantly mediated by mosquitoes, ticks, and sandflies. considering the recent increase in the prevalence of the family virus and its risk potential, we investigated the codon usage pattern to understand its evolutionary processes and provide some useful data to develop the medications for most of flaviviridae viruses. | 2019 | 31346520 |