Crinivirus
Encyclopedia
Crinivirus is a genus of plant virus
es that belong to the family Closteroviridae
. They are also known as the lettuce infectious yellows virus group. They are linear, single-stranded positive sense RNA virus
es (and are therefore group IV).
Examples of species whose entire genome
s have been sequenced
that are currently classified into the genus include the Sweet potato chlorotic stunt virus (SPCSV) and the Lettuce infectious yellows virus (LIYV).
"with a length of 1200-2000 nm and a width of 10-13 nm". The capsid is also described to have "helical symmetry".
s in length. Their genomes also code for protein
s that do not form part of the virion particles as well as structural proteins. The Universal Virus Database describes that their genome sequences near their 3'-ends are capable of hairpin-loop formation and also believe that their 5'-ends may have methylated caps. Each of the viral RNA molecules contains four hair-pin structures and a pseudoknot
in the 3'UTR. The pseudoknot is unusual in that it contains a small stem-loop
structure inside loop L1. In the related genus Closterovirus
, these secondary structures have been found to be important in viral RNA replication.
Plant virus
Plant viruses are viruses that affect plants. Like all other viruses, plant viruses are obligate intracellular parasites that do not have the molecular machinery to replicate without a host. Plant viruses are pathogenic to higher plants...
es that belong to the family Closteroviridae
Closteroviridae
The Closteroviridae are a family of viruses plant viruses with filamentous, helically constructed particles showing distinct cross-banding and varying in length from 650 nanometers to over 2000 nm. The genome is a single strand of positive sense RNA whose size varies from 13 - 19...
. They are also known as the lettuce infectious yellows virus group. They are linear, single-stranded positive sense RNA virus
RNA virus
An RNA virus is a virus that has RNA as its genetic material. This nucleic acid is usually single-stranded RNA but may be double-stranded RNA...
es (and are therefore group IV).
Examples of species whose entire genome
Genome
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....
s have been sequenced
Sequencing
In genetics and biochemistry, sequencing means to determine the primary structure of an unbranched biopolymer...
that are currently classified into the genus include the Sweet potato chlorotic stunt virus (SPCSV) and the Lettuce infectious yellows virus (LIYV).
Virus particle structure
The Universal Virus Database describes that the virions of the genus each consists of a non-enveloped, filamentous capsidCapsid
A capsid is the protein shell of a virus. It consists of several oligomeric structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or may not correspond to individual proteins, are called capsomeres. The capsid encloses the genetic...
"with a length of 1200-2000 nm and a width of 10-13 nm". The capsid is also described to have "helical symmetry".
Genetics
The viruses of this genus have segmented, bipartite genomes that add up to 7,500 -19,500 nucleotideNucleotide
Nucleotides are molecules that, when joined together, make up the structural units of RNA and DNA. In addition, nucleotides participate in cellular signaling , and are incorporated into important cofactors of enzymatic reactions...
s in length. Their genomes also code for protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
s that do not form part of the virion particles as well as structural proteins. The Universal Virus Database describes that their genome sequences near their 3'-ends are capable of hairpin-loop formation and also believe that their 5'-ends may have methylated caps. Each of the viral RNA molecules contains four hair-pin structures and a pseudoknot
Pseudoknot
A pseudoknot is a nucleic acid secondary structure containing at least two stem-loop structures in which half of one stem is intercalated between the two halves of another stem. The pseudoknot was first recognized in the turnip yellow mosaic virus in 1982...
in the 3'UTR. The pseudoknot is unusual in that it contains a small stem-loop
Stem-loop
Stem-loop intramolecular base pairing is a pattern that can occur in single-stranded DNA or, more commonly, in RNA. The structure is also known as a hairpin or hairpin loop. It occurs when two regions of the same strand, usually complementary in nucleotide sequence when read in opposite directions,...
structure inside loop L1. In the related genus Closterovirus
Closterovirus
Closterovirus, also known as beet yellows viral group, is a plant-infecting viral genus included in family Closteroviridae. This genus has a probably worldwide distribution and includes among other viral species the Beet yellows virus and the tentatively assigned Citrus tristeza virus, rather...
, these secondary structures have been found to be important in viral RNA replication.