Term
| What are the two classes of genetic recombination? |
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Definition
| onservative site-specific recombination (CSSR) and transpositional recombination |
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Term
| What is the difference between CSSR and transpositional recombination? |
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Definition
| CSSR is recombination between two defined sequences, while transpositional recombination is recombination between specific and nonspecific DNA sites |
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Term
| What are the two enzymes for sites specific recombination? |
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Definition
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Term
| What is the mechanism of a serine recombination ? |
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Definition
| a side chain of the serine is a OH group. It attacks a bond in the phosphodiester bond and creates a break. The serine then is covalently bound to the DNA backbone. |
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Term
| how many serine recombinase molecules are there are a DNA molecule? |
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Definition
| two , one on each strand. |
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Term
| Where do site specific recombination events occur? |
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Definition
| between two "crossover regions" |
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Term
| Why is the serine recombination mechanism referred to as "conserved? " |
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Definition
| every bond that is broken by the recombinase is reformed later, as a result of the protein continually being covalently attached. Needs no external energy input |
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Term
| What is the main difference between tyrosine and serine recombination mechanisms ? |
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Definition
| tyrosine uses a tyrosine side chain to cut instead of serine, AND it forms two Holliday junctions before being resealed |
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Term
| In site specific recombination, what happens if the recombination sequences being transferred are on the same DNA molecule are in the same identical order, or inverted from eachother? |
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Definition
| a direct repeat for inversion happens if a direct repeat occurs, then the sequence between the two will be delelted...inversion causes inversion |
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Term
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Definition
| a tyrosine recombinase that cleaves at "lox" sites |
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Term
| Which recombinase cleaves all four strands prior to strand exchange? |
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Definition
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Term
| What happens if the recombination sites are on different plasmids? |
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Definition
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Term
| Which site specific recombinase operates on the "one strand at a time exchange" ? |
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Definition
|
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Term
| What is lamda integrase an example of? |
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Definition
| tyrosine recombinase, except uses regaulatory archetecural proteins |
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Term
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Definition
| The function of IHF (integration host factor) is to bring together the lambda Integrase binding sites, thus bending the DNA on the DNA arms |
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Term
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Definition
| Salmonella Hin recombinase is common in bacteria, known as programmed rearrangement. It changes expression of two alternative form of flagellin (H1 and H2 forms). to evade detection of immune system |
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Term
| What is the DNA enhancer in Hin Recombination? |
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Definition
| Fis stimulates the rate of recombination ~1,000-fold (When Fis protein is present, the three-segment complex “invertasome” can form). |
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Term
| What are the two types of transposition? |
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Definition
| cut and paste and replicative |
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Term
| Where are transposases coded? |
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Definition
|
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Term
| Is the DNA copied in the cut and paste method? |
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Definition
| no, just transferred somewhere else |
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Term
| How many transposases are found on a transposon and where do they bind? |
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Definition
| 2 per molecule , and they bind to the inverted repeats on the end |
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Term
| When does the transposome occur? |
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Definition
| When the transposases come close toegether and are about to cut at the same time |
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Term
| What is the product of the transposase exccision? |
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Definition
|
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Term
| What forms the hairpin loops on the end of the transposon? |
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Definition
| the opposing 3' OH groups, but then they get cleaved again by the transposase |
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Term
| How are double stranded breaks fixed in transposition? |
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Definition
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Term
| How is the intermediate for transposition different in the replicative model ? |
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Definition
| the transposome isn't cut out before attacking the phosphodiester backbone of another chromosome, its 5' ends are still attached to the transposase |
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Term
| What is the difference between an autonomous transposon and a nonautonomous transposon? |
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Definition
| autonomous carries all the elements of transposition it needs, nonautonomous doesn't |
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Term
| What mechanism of transposition do Tn10 operate in ? |
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Definition
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Term
| Within the Tn10 transposon, which composite transposons are autonomous and which one is nonautonomous |
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Definition
| IS10L is nonautonomous, whereas IS10R and Tn10 are autonomous |
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Term
| What is another name of a poly-A retrotransposon? |
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Definition
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Term
| Why is it that poly-A retrotransposons cannot transpose again ? |
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Definition
| it loses its promoter when it gets converted back into cDNA |
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Term
| where does the retro transcription polymerase come from in the mechanism of poly-A retrotransposons? |
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Definition
| it is coded for within the transposon |
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Term
| What is special about the IS4-Family Transposons ? Name a transposon in this family |
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Definition
their P(out) promoter regulates the RNAi antisense RNA that will in turn suppress the expression of the transposase
ex. Tn10 |
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Term
| How does the Tn10 transposon regulate its timing of the transposons jumping? |
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Definition
| it methylates the transposons during cell replication |
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Term
| where do all transposases bind? |
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Definition
| TLR terminal inverted repeats |
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Term
| What type of transposon is a Sleeping Beauty? |
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Definition
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Term
| Where do Ty elements like to jump into ? |
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Definition
|
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Term
| are LINES autonomous or nonautonomous |
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Definition
|
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Term
|
Definition
| nonautonmous poly-A retrotransposons |
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Term
|
Definition
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Term
| How to avoid transposing cellular mRNA molecules? |
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Definition
| LINE encoded proteins immediately bind to their own RNA during translation |
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