Insertion Sequences, Transposon, Integrons 1

Question 1

Breaking and rejoining of DNA in new combinations

Answer 1

Recombination

Question 2

Difference between homologous and nonhomologous recombination

Answer 2

Sequences in homologous are similar while in nonhomologous are not

Question 3

A form of nonhomologous recombination where genetic elements hop or transfer from one chromosome and/or plasmid to another

Answer 3

Transposition

Question 4

Is transposition found in all organisms?

Answer 4

Yes

Question 5

____ is the source of the transposon and ____ is the destination DNA of the transposon

Answer 5

Donor DNA; Recipient DNA

Question 6

Transposition is tightly regulated and occurs only once in every __ to __ cell divisions

Answer 6

10^3 to 10^8

Question 7

Are reverse complementary regions at the ends of transposons. Within this is the transposase gene and other DNA segments

Answer 7

Inverted repeats

Question 8

Transposition where similar sequences are on the same strand

Answer 8

Direct repeats

Question 9

Composed of mRNA introns that cleave and re-insert themselves to a new insertion site as mRNA

Answer 9

Mobile Group II

Question 10

Transposition which behaves like retroviruses

Answer 10

Retrotransposons

Question 11

Short transposon sequences that often only include the sequence for the transposon itself. These often deactivates a gene when it inserts into it

Answer 11

Insertion sequence elements

Question 12

E. coli contains what insertion sequences

Answer 12

IS1, IS2, IS3, IS4

Question 13

Two IS elements of the same type that bracket a certain number of genes. Anything in between can be transferred including other IS elements

Answer 13

Composite transposons

Question 14

IS elements that bracket enough genes and an origin of replication

Answer 14

IS elements that form plasmids

Question 15

The gene inserted itself within the transposon gene. The genes are between two IR instead of two similar IS

Answer 15

Noncomposite transposons

Question 16

In noncomposite transposons, they are inserted as a _____ by an ______ through recombination

Answer 16

Casette; Integron

Question 17

Plasmids that do not replicate once integrated onto the host

Answer 17

Suicide vectors

Question 18

Two types of suicide vectors

Answer 18

Phage suicide vectors and plasmid suicide vectors

Question 19

Detection of transposon where transfer of transposon from mobilizable to non-mobilizable plasmid

Answer 19

Mating out assay

Question 20

Mode of transposition when a transposon forms a copy that cointegrates and eventually resolves to the target DNA

Answer 20

Replicative transposition

Question 21

Formation of _____ between recipient donor DNA after making a copy of the transposon
Resolution of cointegrate by ____ at the res sites

Answer 21

Cointegrate; Resolvase

Question 22

In transposon inverted repeats, IR are sites where ____ act upon

Answer 22

TnpA

Question 23

In transposon inverted repeats, the gene ____ represses tnpA and promotes site-specific recombination between 2 copies of the same transposon in the res sites

Answer 23

tnpR

Question 24

Difference between mutations in tnpA and tnpR and res

Answer 24

Mutation in tnpA= can affect transposition
Mutation in tnpR= cause cointegration and higher than normal transposition rates
Mutation in res= cointegration

Question 25

Mode of transposition also called as cut and paste transposition. Entire transposon is removed from donor DNA then relocated to the recipient DNA

Answer 25

Conservative transposition

Question 26

How do you repair conservative transposition

Answer 26

Homologous recombination with a sister chromosome or plasmid repairs the missing parts in the donor DNA

Question 27

____ and ____ undergo precise excisuon of only the transposon

Answer 27

Tn5 and Tn10

Question 28

Mode to transposition where It is rare and often DNA repair mechanisms restore the cut transposon; no cointegrase and no resolvase needed

Answer 28

Precise excision

Question 29

DDE transposons stand for? And functions in chelating ___

Answer 29

2 Aspartate (D) and one glutamase (E); Mg2+

Question 30

Mutations in TnsA in Tn7 results in ____ instead of _____ transposition

Answer 30

Replicative; conservative

Question 31

A 5’-end of the transposon is broken in ________ to form an intermediate hairpin loop as the transposon seperates from donor DNA

Answer 31

Conservative transposition

Question 32

Explain the modes of transposition of IS2, IS3, and IS911

Answer 32

Features both replicative and conservative;
One strand is excused and turned into circular ssDNA
Replication to circular ssDNA before insertion to recipient DNA
Replication of remaining ssDNA in donor DNA to become dsDNA

Question 33

Similar to rolling circle replication and source of antibiotic resistance; what is its other name?

Answer 33

Y2 or rolling circle replication; ISCR/insertion sequence common region elements

Question 34

In rolling circle transposition, the 3’-end serve as what

Answer 34

Primer to become double-stranded after excision

Question 35

True or false: No transposable element randomly inserts itself into any target DNA

Answer 35

True; weak site preferences making the transposition look like it transfers randomly

Question 36

TnpR represses transposase gene in

Answer 36

Tn3

Question 37

Transposition only occurrs if replication fork has already passed through

Answer 37

Tn10

Question 38

Transfer to a site in the DNA not close to another similar transposon

Answer 38

Target site immunity