Question

The table shows where different restriction endonucleases (restriction enzymes) cleave DNA. The abbreviation R represents the purines (adenine and guanine). The pyrimidines (cytosine, thymine, and uracil) are abbreviated as Y. The abbreviation W represents adenine or thymine. Enzyme EcoRI EcoRV Target sequence 5' GAATTC 3' 3' CTTAAG 5 5' GATATC 3 3' CTATAG 5 5' GGCC 3 3' CCGG 5 5' AAGCTT 3' 3' TTCGAA 5 5'RGGWCCY 3 3' YCCWGGR 5 Cleavage 5'G AATTC 3' 3' CTTAA G5 5'GAT ATC 3' 3' CTA TAG 5 5'GG CC3 3' CC GG 5 5A AGCTT 3' 3' TTCGA A5 5'RG GWCCY 3' 3' YCCWG GR 5' HaeIII HindIII PpUMI Which restriction endonuclease(s) would cleave a DNA molecule at the given sequences? a) 5' GCCAATTGAAGCTT 3' b) 5' AAAGCTTGTGATATC 3' EcoRI EcoRI HaeIII EcoRV HindIII EcoRV HindIII HaelII c) Plasmid DNA and a gene of interest are cut with the enzyme PpUMI. Write a possible sequence of bases for the sticky end of the gene in the 5' to 3' direction. possible sequence of bases:

Need Part C answered only.

Answer 1

Answer for part "c"

The given restriction digestion site for PpuMI is as follows:

5' - RG   GWC CY - 3'

3' - YC CWG   GR - 5'

The 5' - 3' sticky end of the gene must be complementary to the 3'-5' sticky end of the complementary DNA strand, i.e. 3'-CWG-5'. As per the information in the question, W can indicate either A or T. Thus, this sticky end can be written as:

3'-CWG-5' =   3'-CAG-5' or 3'-CTG-5'

So, the two possible 5'-3' sticky ends of the gene will be: 5'-GTC-3' and 5'-GAC-3', which will be complementary to 3'-CAG-5' and 3'-CTG-5', respectively.