DNA

Part:BBa_K3897001

Designed by: Connor   Group: iGEM21_GreatBay_SCIE   (2021-10-01)
Revision as of 01:17, 9 October 2021 by SoniaPeh (Talk | contribs)


pH-sensitive DNA switch

A pH-sensitive DNA nanoswitch, which folds into triplex under low pH and duplex under high pH.

Mechanism

Conventional base-pairing present in DNA between A-T and C-G are known as Watson-Crick base pairing denoted as "-", also known as complementary base pairing. However, another type of pairing exists as well, known as Hoogsteen base pairing. One of the bases of A-T or C-G is flipped, and hydrogen bonds hold them together as well. However, C·G hoogsteen bonds (denoted as "·")require protonation of Cytosineto form one essential hydrogen bond.

Figure 1 Watson-Crick& Hoogsteen base pairing.[1]Re-illustrated by Anthea.

Thus, a DNA switch can be designed to be pH-sensitive. As shown in Figure 2, the DNA can fold into a triplex under low pH, and unfold into a duplex at high pH. Due to the protonation of cytosine to form C·G bonds, regulating the amount of C·G and A·T present in the switch could regulate its threshold value of folding.



Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    COMPATIBLE WITH RFC[12]
  • 21
    COMPATIBLE WITH RFC[21]
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    COMPATIBLE WITH RFC[25]
  • 1000
    COMPATIBLE WITH RFC[1000]



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