How to solve restriction mapping problems?

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SUMMARY

The discussion focuses on constructing a restriction map from a linear DNA sequence of 1000bp digested by four enzymes: E, B, P, and S. The sizes of the fragments produced by each enzyme and their combinations are provided. Key insights include recognizing that enzyme B must have cut the 773bp fragment into smaller pieces when combined with E, and the absence of a 450bp fragment in the E+B combination suggests a specific restriction pattern. The participants emphasize the need to visualize potential maps and systematically rule out possibilities using all enzyme data.

PREREQUISITES
  • Understanding of restriction enzymes and their function in DNA digestion
  • Familiarity with constructing restriction maps
  • Knowledge of fragment size analysis in molecular biology
  • Basic skills in interpreting experimental data from enzyme digests
NEXT STEPS
  • Learn how to construct a restriction map using software tools like SnapGene or Benchling
  • Study the principles of enzyme digestion and fragment size analysis
  • Explore case studies of restriction mapping in molecular biology
  • Investigate the implications of restriction site patterns on genetic engineering
USEFUL FOR

Molecular biologists, genetic engineers, and students studying DNA manipulation techniques will benefit from this discussion, particularly those interested in restriction mapping and enzyme analysis.

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Homework Statement


A piece of linear DNA 1000bp long is completely digested by four enzymes, E, B, P, and S.
We are given the sizes of fragments (in bp) produced when each of the enzymes are used in isolation, and when they are used in different combinations:
E : 227, 773
B : 150, 450, 400
P : 400, 600
S : 206, 794
E + B : 223, 227, 400, 150
E + P : 227, 373, 400
B + S : 56, 150, 344, 450
P + S : 194, 206, 600

Homework Equations


Not applicable

The Attempt at a Solution



I understand that with E + B, for example, as 227, 400, and 150 bp are present, enzyme B must have cut the 773 fragment into three pieces, 223, 400, and 150. I really don't know how to piece this information together to make a restriction map, it doesn't make any sense to me.
 
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Hello foldy, :welcome:

The problem statement is missing a question. Could it be it's incomplete ?
You seem to know what a restriction map is; could you elucidate ?

In the mean time I notice E+B has no 450 base-pair sized chunks. Could that be the consequence of one of the restrictions ?
 
BvU said:
Hello foldy, :welcome:

The problem statement is missing a question. Could it be it's incomplete ?
You seem to know what a restriction map is; could you elucidate ?

In the mean time I notice E+B has no 450 base-pair sized chunks. Could that be the consequence of one of the restrictions ?
Thanks for your reply!
Yes, apologies for that, there isn't a question as such; I need to construct a restriction map from this data. My question is how do I do this?
A restriction map shows all the positions of the restriction sites in a piece of DNA, which has information such as the length of the fragments and the enzyme responsible for each restriction site.
Yes, I think that with the E + B combination, enzyme E must have cut into the 450 fragment, dividing it into 227 bp and 223 bp. I'm just not sure how to go from recognising points such as these to constructing the full restriction map.
 
Can you try drawing the different possible maps that are consistent with the E, B, and E+B digests? After you have those possibilities, consider the other two restriction enzymes and use those data to try ruling out some of the maps.
 

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