14 | Transposition

Question 0

Transposition

Answer 0

The movement of a transposon from one part of DNA sequence to another without any regard for surrounding DNA

Question 1

Transposable elements

Answer 1

Also known as Transposons, are nucleic acid sequences that insert themselves into the genome of another organism and are replicated passively every time a cell divides

Question 2

Site-specific recombination

Answer 2

Precise and predictable mechanism by which DNA is switched between two specific sequences

Question 3

Lysogenic pathway

Answer 3

Incorporation of phage genome as part of host genome whether via integration or as an autonomous plasmid

Question 4

Prophage

Answer 4

Lysogenized phage genome

Question 5

Lytic pathway

Answer 5

Packaging and replication of bacteriophage genome into new phage heads culminating in lysis destruction of host cell and dispersal of progeny

Question 6

Bacterial transduction

Answer 6

Low-frequency whereby bacterial genes are transported and incorporated into another bacteria

Question 7

Cre-lox

Answer 7

Promotion of bacterial chromosome circularization by phage-encoded site-specific recombination at recombination site known as loxP and the recombinase Cre

Question 8

Cre

Answer 8

(cyclization recombination)

Recombinase that targets loxP sites during promotion of bacterial chromosome circularization

Question 9

Phase variation

Answer 9

Regulation mechanism that evades host immune response by switching between distinctly different flagellin proteins every 1,000 generation or so

Question 10

Donor

Answer 10

Location from which transposon originates before “jumping”

Question 11

Target site

Answer 11

Destination of transposon upon “jumping”

Question 12

Three primary pathways of Transposition

Answer 12

(1) Cut & Paste
(2) Replicative
(3) Via RNA intermediate

Question 13

Two primary components of a transposable element…

Answer 13

(1) DNA element

(2) Enzyme

Question 14

Transposase

Answer 14

Enzyme that catalyses transposition

Question 15

Cointegrate

Answer 15

Intermediate of replicative transposition comprised of donor region covalently linked to DNA at target site

Question 16

Retrotransposable element

Answer 16

Also known as a retrotransposon, produces an RNA intermediate during process of transposition

Question 17

Reverse transcriptase

Answer 17

Specialized enzyme of retrotransposon that can use either RNA or DNA as template strand to synthesize DNA

Question 18

Two Majors steps of Retrotransposition

Answer 18

Reverse transcriptase generates double-stranded DNA from single-stranded RNA by:

(1) RNA intermediate is first used to create complimentary DNA strand resulting in RNA-DNA hybrid duplex
(2) That DNA strand is then used as template to complete second DNA strand and RNA is digested by RnaH

Question 19

Extrachromosomally Primed Retrotransposon

Answer 19

Make use of aspects of both “cut-and-paste” and “replicative” transposition systems

Question 20

Integrase

Answer 20

Catalyses insertion of free-DNA transposon into target site

Question 21

Target-primed retrotransposon

Answer 21

Non-LTR (long-terminal repeat) elements liberated from 3’ end of DNA synthesis primer

Question 22

Insertion sequence

Answer 22

Simple transposons that contain only the sequences required for transposition and genes for the proteins (transposases) that promote it

Question 23

Composite transposon

Answer 23

Contain one or more genes in addition to those necessary for transposition

Question 24

Complex transposon

Answer 24

Possess larger genomes for accessory proteins and enzymes that may activate or assist in processes other than transposition

Question 25

Retroviruses

Answer 25

RNA virus that contains reverse transcriptase

Question 26

cDNA

Answer 26

(Complimentary DNA)

Synthetic DNA prepared from mRNA template and a complimentary DNA strand and catalyzed by reverse transcriptase

Question 27

DDE motif

Answer 27

A critical active site constituting of non-adjacent residues (D,D & E)