Gary Foster Flashcards
TMV structure
- Rod particle; 300nm long, 18nm in diameter
- 95% protein, 5% RNA
- Extremely stable
- Comprises of ca. 2130 subunits in a helical array
- 3 nucleotides of RNA per subunit
- Right handed helix, 49 nucleotides and 16.34 subunits per turn
- Central canal has a radius of ca. 2nm
- Coat protein – 17.6 kDa
- Movement protein – 30 kDa
- Replicases – 126/183 kDa
experiment to proof that genomic RNA exists
Heinz Fraenkel-Conrat
1- In vivo construction of a hybrid virus
2- Two strains of the same virus (red and black)
3- Two strains of virus separated into constituent protein and RNA
4- The protein of one strain allowed to recombine with the RNA of the other
5- The in vivo progeny of the hybrid had the protein originally associated with the nucleic acid.
Virus Replication Strategies
- Polyproteins
- Subgenomic mRNAs
- Multipartite genomes
- Internal initiation
- Leaky scanning
- Non-AUG start codons
- Transactivation
- Translational (ribosome) shunt
- Read-though proteins
- Frameshift proteins
- Splicing
- Translation for both viral and complementary strands
CaMV viral properties
Encodes 6 proteins:
- Cell-to-cell movement protein (P1)
- Two aphid transmission factors (P2 & P3)
- Precursor of capsid proteins (P4)
- Polyprotein precursor of: proteinase, reverse transcriptase & ribonuclease H (P5)
- Inclusion body protein/translation transactivator (P6)
Detection and Identification of Plant Viruses
Biological assays - Tester plants Electron microscopy (EM) - TEM/SEM Serological assays - ELISA Hybridization procedures Polymerase chain reaction (PCR) - Multiplex, qRT-PCR, Degenerate PCR
what ELISA stands for
enzyme linked immuno-sorbent assay
What is multiplex PCR
testing for viruses present in a plant
Use multiple primer sets to produce amplicons of varying sizes at the same time
Enables targeting of multiple viruses at once
Saves time and reagents
What makes SYBR green fluoresce?
when bound to dsDNA
