Midterm 2 - Notes 6 (Part 3)

Question 1

Right border sequences

Answer 1

Enable the left border of an A. tumefaciens nopaline Ti-plasmid to produce ssDNA
- transfer is initiated here

Question 2

Left border sequences

Answer 2

This is where the transfer is terminated

- T-DNA region is defined and ready to be cut out

Question 3

T-DNA region

Answer 3

This is the area transferred from the bacterium to the plant cell

Question 4

Virulence region

Answer 4

Contains all the genes that are necessary to transfer the T-DNA from the bacterium to the plant cell

Question 5

What is the virulence region and T-DNA required for?

Answer 5

Tumour formation

- cant form without it

Question 6

What happens if you only have virulence but not T-DNA?

Answer 6

No tumour formation will take place

Question 7

Conjugation

Answer 7

Is the transfer of genetic material form one bacterial cell to another, either through direct contact or a bridge between the 2 cells

Question 8

Opine catabolism

Answer 8

Allows a specific set of opines to be catalyzed

Question 9

OriT

Answer 9

Origin of transfer

Question 10

Origin of transfer

Answer 10

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

Question 11

Ti plasmid

Answer 11

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

Question 12

What origin is the genes of the T-DNA?

Answer 12

Bacterial origin

Question 13

What are 2 examples of auxin?

Answer 13

1. iaaH

2. iaaM

Question 14

What is the mutant phenotype for auxin? (2)

Answer 14

1. Tumour formation + adventitious shoots
2. Cytokinin levels still elevated
   - but auxin levels did not increase

Question 15

What is not found in plants?

Answer 15

Homologs

- so they must get it a different way

Question 16

The auxin produced is chemically identical to what?

Answer 16

Endogenous plant auxin

• employ a biosynthetic route that is different form the plant pathway
• contain regulatory elements active in eukaryotes

Question 17

What is auxin biosynthesis catalyzed by?

Answer 17

Plant and agrobacterium gene products (enzymes)

Question 18

What is the mutant phenotype for the gene 6B? (2)

Answer 18

1. Smaller tumours in some plants

2. Auxin and cytokinin levels still elevated

Question 19

What can gene 6B induce?

Answer 19

Small tumours independent of other oncogenes

- no elevated growth hormones needed

Question 20

What may gene 6B alter?

Answer 20

Gene sensitivity of plant cells to phytohormones

Question 21

What does the gene 6B encoded protein not have?

Answer 21

Homology to characterized proteins

Question 22

What does the gene 6B contain?

Answer 22

An acidic domain

Question 23

What did they start looking at but ended up being a weak starting point?

Answer 23

Protein protein interactions

Question 24

What 3 things does the mutation of the gene 6B no effect?

Answer 24

1. Acts as independent
2. Has an enhancing factors because if you use it, it gets smaller
3. If you use it all on you own and put it in the plant then you get a formation if tumour in these plants

Question 25

Is gene 6B by itself sufficient to create tumours on its own?

Answer 25

Yes

Question 26

What does the acidic domains of gene 6B contain? (2)

Answer 26

1. Rich in glutamic acid

2. Rich in aspartic acid

Question 27

What is the acidic domain necessary for?

Answer 27

Tumour induction/formation

Question 28

What is found in the natural setting for 6B? (2)

Answer 28

1. Promoter

2. GenX

Question 29

What is found in the artificial yeast-2-hybrid system? (2)

Answer 29

1. Promoter

2. Reporter/marker

Question 30

What was 6B cloned into?

Answer 30

Bait vector

Question 31

What does it mean if you see expression of the reporter genes?

Answer 31

There is direct interaction between proteins

- prey and bait proteins

Question 32

What was cloned into the prey vector?

Answer 32

Plant cDNA library

Question 33

What was being screened?

Answer 33

Marker gene expression

Question 34

What did they find after the screening? (2)

Answer 34

1. 10 clones survived in absence of His
2. Correspond to 2 cDNAs
   - one was furthered analyzed
   - -> SIP1