UID:
edoccha_9961427243702883
Format:
1 videorecording (40 mins., 34 sec.) :
,
sound, color
,
004034
Note:
Retrieved April 12, 2024, from https://hstalks.com/bs/936/.
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Introduction -- Altering the sizes of DNA bases -- Two design strategies -- Benzo-expansion strategy -- xDNA: long-term goals -- xDNA = "expanded DNA" -- Structure of adenine and xA -- Structure of thymine and xT -- Size expanded base pairs: too wide for DNA? -- Lack of backbone distortion -- Synthesis of dxA nucleoside phosphoramidite -- Synthesis of dxT nucleoside phosphoramidite -- xDNA bases are fluorescent -- A single expanded pair destabilizes DNA -- When all pairs are expanded, xDNA is very stable -- xDNA can form highly stable helices -- A four-base expanded-size genetic system -- High stability of xDNA compared to DNA -- xDNA hybridization is sequence and size selective -- Solution structure of an xDNA helix -- Major groove -- Minor groove -- Enhanced stacking overlap due to larger base pair -- Strong stacking of size-expanded bases -- yDNA = "wide DNA" -- A new strategy for widening bases: "yDNA" -- The four building blocks of yDNA -- yDNA bases are fluorescent -- Six sequences of yDNA -- Conclusions of xDNA studies to date -- Future plans for xDNA / yDNA -- Two design strategies -- The concept of nonpolar shape mimics -- Thymine and difluorotoluene -- The ability to process non-H-bonding bases -- Single nucleotide insertions -- Efficiency and fidelity for dNTP insertion -- New hypothesis -- Varying steric demand -- Modeling pairs of increasing size -- Increasing steric demand series -- Predictions for DNA polymerase -- Varying steric demand in an enzyme active site (1) -- Varying steric demand in an enzyme active site (2) -- Trends in efficiency: sub-Angstrom increments -- Trends in fidelity across the series -- The goldilocks principle (1) -- The goldilocks principle (2) -- Observations -- Biological relevance? -- The importance of steric effects in vivo -- Conclusions to date -- Why do polymerases prefer larger DNA? -- Questions remaining -- Future plans -- Acknowledgements.
Language:
English
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