Biomod/2011/Caltech/DeoxyriboNucleicAwesome/Sequence Design

Thursday, April 18, 2024 Home Members Project Protocols Progress Discussion References

Sequence Design Design Process After having designed our mechanism at the domain level, we needed to fill in our domains with actual sequences. To start, we picked specific lengths for each of our domains. We decided to stick with the general precedent that toeholds be 6 nucleotides in length, then decided that any domain that was part of a probe be 20 nucleotides in length, as this length is both not wastefully long and long enough to ensure that no spontaneous dissociation would occur. We then decided that any domain longer than a toehold, but not part of the probe system should be 15 base pairs in length, as this would not spontaneously dissociate, but could be easily strand displaced. After these numbers were decided, we consulted a list of 20 nucleotide sequences that are known to be relatively inert and chose sequences from this list to fill in our 20 and 15 nucleotide domains. We used NUPACK and a little trial and error to find our 7 necessary relatively inert toeholds. We then ran a number of simulations in NUPACK to check for unwanted secondary structures and interactions in our designed sequences. List of Domains Probe Domains The length of these sequences is 20 nucleotides. Domain Name Sequence (5' → 3') Complement Sequence (5' → 3') Ptr1 CCAACTCAACCCATTTCATC GATGAAATGGGTTGAGTTGG Ptr2 TACATACACCAACCTCCACC GGTGGAGGTTGGTGTATGTA lp† TTTTTTTTTTTTTTTTTTTTTTTTTTT AAAAAAAAAAAAAAAAAAAAAAAAAAA upca ACCTTACCTCTCCCTAACTT AAGTTAGGGAGAGGTAAGGT upcg ACTAACTCCTACCCACACCT AGGTGTGGGTAGGAGTTAGT Pwg CCTCTTTCTTATCACTTCAA TTGAAGTGATAAGAAAGAGG † The lp domain is 27 nucleotides long. Toehold Domains The length of these sequences is 7 nucleotides. Domain Name Sequence (5' → 3') Complement Sequence (5' → 3') a1 CTCCTC GAGGAG a2 ATCCAC GTGGAT a2' † ATCC GGAT z AAAAAA TTTTTT l CCATTC GAATGG u ACACAC GTGTGT wi GGTAAG CTTACC cgi ATGTTG CAACAT cgd ‡ AGATGA TCATCT wgd ‡ AGATGA TCATCT † The a2' domain is a subset of the a2 domain and is 4 nucleotides long. ‡ Toeholds cgd and wgd are the same. This does not change the function of our system because they are never used in the same solution together. Other Domains The length of these sequences is 15 nucleotides. Domain Name Sequence (5' → 3') Complement Sequence (5' → 3') b CCTCAAAACTTATCC GGATAAGTTTTGAGG x TATCTCCTTTCTATT AATAGAAAGGAGATA List of Strands Domain Name Length Sequence (5' → 3') b CCTCAAAACTTATCC GGATAAGTTTTGAGG x TATCTCCTTTCTATT AATAGAAAGGAGATA