What are the 7 steps of viral replication?
As discussed above, they are carried out in a series of 7 steps that is: attachment, penetration and entry, uncoating, replication, synthesis of virus components, assembly of virions and lastly the release of virions.
How do ssDNA viruses replicate?
Most ssDNA viruses contain circular genomes that are replicated via rolling circle replication (RCR). ssDNA RCR is initiated by an endonuclease that bonds to and cleaves the positive strand, allowing a DNA polymerase to use the negative strand as a template for replication.
How do Ssrna viruses replicate?
RNA viruses replicate their genomes via one of two unique pathways—either by RNA-dependent RNA synthesis, or among the retroviruses, by RNA-dependent DNA synthesis (reverse transcription) followed by DNA replication and transcription.
What are the 5 stages of viral replication?
The life cycle of viruses can differ greatly between species and category of virus, but they follow the same basic stages for viral replication. The viral life cycle can be divided into several major stages: attachment, entry, uncoating, replication, maturation, and release.
What are the 6 stages in viral replication?
The virus life cycle could be divided into six steps: attachment, penetration, uncoating, gene expression and replication, assembly, and release.
What are the two types of viral replication?
There are two processes used by viruses to replicate: the lytic cycle and lysogenic cycle. Some viruses reproduce using both methods, while others only use the lytic cycle.
Can single-stranded DNA replicate?
DNA polymerases (DNAPs) are responsible for the synthesis of a new DNA strand on a single-stranded (ss) template (1). They play a key role in the replication, repair, and proofreading of DNA by catalyzing the addition of a complementary dNTP to the 3′ end of the growing strand.
Can mRNA be made from ssDNA?
Class II: ssDNA
This can be used to both manufacture viral proteins and as a template for viral genome copies. For the minus-strand DNA viruses, the genome can be used directly to produce mRNA but a complementary copy will still need to be made, to serve as a template for viral genome copies.
Where do positive RNA viruses replicate?
6 Virus replication sites. Positive-strand RNA viruses are known to replicate in the cytoplasm of the host cell in association with membranes.
Where do RNA viruses replicate?
RNA replication occurs in the cytoplasm and is carried out by the viral RNA polymerase. The full length plus strand is coated with nucleocapsid protein as it is made (mRNAs are not coated with this protein, which would interfere with the host protein translation machinery).
What are the two types of virus replication?
There are two processes used by viruses to replicate: the lytic cycle and lysogenic cycle. Some viruses reproduce using both methods, while others only use the lytic cycle. In the lytic cycle, the virus attaches to the host cell and injects its DNA.
Which is the correct order of viral replication?
Viral replication involves six steps: attachment, penetration, uncoating, replication, assembly, and release. During attachment and penetration, the virus attaches itself to a host cell and injects its genetic material into it.
What is the viral replication cycle called?
What is the replication cycle of a virus?
In general terms, virus replication involves three broad stages which are present in all viruses: initiation of infection, replication and expression of the genome, and the release of mature virions from the infected cell.
What are the 3 types of viruses?
- Macro viruses – These are the largest of the three virus types.
- Boot record infectors – These viruses are known also as boot viruses or system viruses.
- File infectors – These viruses target .
What is the difference between RNA and single-stranded DNA?
Due to its deoxyribose sugar, which contains one less oxygen-containing hydroxyl group, DNA is a more stable molecule than RNA, which is useful for a molecule which has the task of keeping genetic information safe. RNA, containing a ribose sugar, is more reactive than DNA and is not stable in alkaline conditions.
What is the difference between single and double stranded DNA?
ssDNA is a linear structure that has only one DNA strand. dsDNA has two DNA strands bound by hydrogen bonds in a helical fashion. It is found in a few viruses. It is a less stiff and stable structure.
What are the 7 types of viral genomes?
The ICTV classifies viruses into seven orders: Herpesvirales, large eukaryotic double-stranded DNA viruses; Caudovirales, tailed double-stranded DNA viruses typically infecting bacteria; Ligamenvirales, linear double-stranded viruses infecting archaea; Mononegavirales, nonsegmented negative (or antisense) strand single …
What are the 7 classifications of viruses?
- Group I: double-stranded DNA viruses.
- Group II: single-stranded DNA viruses.
- Group III: double-stranded RNA viruses.
- Group IV: positive sense single-stranded RNA viruses.
- Group V: negative sense single-stranded RNA viruses.
- Group VI: single-stranded RNA viruses with a DNA intermediate.
What is the difference between positive and negative strand RNA?
The main difference between positive and negative sense RNA virus is that positive sense RNA virus consists of viral mRNA that can be directly translated into proteins whereas negative sense RNA virus consists of viral RNA that is complementary to the viral mRNA.
What is positive and negative RNA?
The key difference between the negative and positive sense RNA virus is that the negative sense RNA virus comprises viral RNA, which is complementary to the viral mRNA, while positive sense RNA virus comprises viral mRNA, which can be translated into proteins directly.
What RNA is responsible for replication?
RNA dependent RNA polymerase (RdRp) is one of the most versatile enzymes of RNA viruses that is indispensable for replicating the genome as well as for carrying out transcription.
Which RNA virus replicates in the nucleus?
Influenza viruses replicate within the nucleus of the host cell. This uncommon RNA virus trait provides influenza with the advantage of access to the nuclear machinery during replication.
Which stage of virus occurs first?
Attachment is the first stage in the infection process in which the phage interacts with specific bacterial surface receptors (e.g., lipopolysaccharides and OmpC protein on host surfaces).