Midterm 2 - Notes 6 (Part 3) Flashcards
Right border sequences
Enable the left border of an A. tumefaciens nopaline Ti-plasmid to produce ssDNA
- transfer is initiated here
Left border sequences
This is where the transfer is terminated
- T-DNA region is defined and ready to be cut out
T-DNA region
This is the area transferred from the bacterium to the plant cell
Virulence region
Contains all the genes that are necessary to transfer the T-DNA from the bacterium to the plant cell
What is the virulence region and T-DNA required for?
Tumour formation
- cant form without it
What happens if you only have virulence but not T-DNA?
No tumour formation will take place
Conjugation
Is the transfer of genetic material form one bacterial cell to another, either through direct contact or a bridge between the 2 cells
Opine catabolism
Allows a specific set of opines to be catalyzed
OriT
Origin of transfer
Origin of transfer
Is essential for replication and mobilization of gene
- DNA replication by the rolling circle mode produces a ss copy of the plasmid DNA that moves through the pore to the recipient cell
Ti plasmid
Is a plasmid that often is a part of the genetic equipment that A. tumefaciens and A. zhizogenes used to transduce their genetic material to plants
What origin is the genes of the T-DNA?
Bacterial origin
What are 2 examples of auxin?
- iaaH
2. iaaM
What is the mutant phenotype for auxin? (2)
- Tumour formation + adventitious shoots
- Cytokinin levels still elevated
- but auxin levels did not increase
What is not found in plants?
Homologs
- so they must get it a different way
The auxin produced is chemically identical to what?
Endogenous plant auxin
- employ a biosynthetic route that is different form the plant pathway
- contain regulatory elements active in eukaryotes
What is auxin biosynthesis catalyzed by?
Plant and agrobacterium gene products (enzymes)
What is the mutant phenotype for the gene 6B? (2)
- Smaller tumours in some plants
2. Auxin and cytokinin levels still elevated
What can gene 6B induce?
Small tumours independent of other oncogenes
- no elevated growth hormones needed
What may gene 6B alter?
Gene sensitivity of plant cells to phytohormones
What does the gene 6B encoded protein not have?
Homology to characterized proteins
What does the gene 6B contain?
An acidic domain
What did they start looking at but ended up being a weak starting point?
Protein protein interactions
What 3 things does the mutation of the gene 6B no effect?
- Acts as independent
- Has an enhancing factors because if you use it, it gets smaller
- If you use it all on you own and put it in the plant then you get a formation if tumour in these plants
Is gene 6B by itself sufficient to create tumours on its own?
Yes
What does the acidic domains of gene 6B contain? (2)
- Rich in glutamic acid
2. Rich in aspartic acid
What is the acidic domain necessary for?
Tumour induction/formation
What is found in the natural setting for 6B? (2)
- Promoter
2. GenX
What is found in the artificial yeast-2-hybrid system? (2)
- Promoter
2. Reporter/marker
What was 6B cloned into?
Bait vector
What does it mean if you see expression of the reporter genes?
There is direct interaction between proteins
- prey and bait proteins
What was cloned into the prey vector?
Plant cDNA library
What was being screened?
Marker gene expression
What did they find after the screening? (2)
- 10 clones survived in absence of His
- Correspond to 2 cDNAs
- one was furthered analyzed
- -> SIP1
