DNA Nanotechnology
Nadrian C.
Seeman*, Hui Wang, Xiaoping Yang,
Furong Liu, Chengde Mao, and Lisa Wenzler
Department of Chemistry
New York University
New York, NY 10003, USA |
This is an abstract
for a talk to be given at the
Fifth
Foresight Conference on Molecular Nanotechnology.
The full paper is now available.
In recent years, we have spent a great deal of effort to
construct molecular building blocks from unusual DNA motifs. DNA
is an extremely favorable construction medium: The sticky-ended
association of DNA molecules occurs with high specificity, and it
results in the formation of B-DNA, whose structure is well known.
The use of stable branched DNA molecules permits one to make
stick-figures. We have used this strategy to construct a
covalently closed DNA molecule whose helix axes have the
connectivity of a cube,
and a second molecule, whose helix axes have the connectivity of
a truncated
octahedron .
In addition to branching topology, DNA also affords control of
linking topology, because double helical half-turns of B-DNA or
Z-DNA can be equated, respectively, with negative or positive
crossings in topological objects. Consequently, we have been able
to use DNA to make four
topological species , [circle, trefoil knots of both signs
and a figure-8 knot] from a single strand. By making RNA knots,
we have discovered the existence of an RNA
topoisomerase. It is possible that branched objects could be
made by PCR or biological replication by transforming their
catenated topologies to knotted
topologies. DNA-based topological control has also led to the
construction of Borromean Rings,
which could be used in DNA-based computing applications.
The key feature previously lacking in DNA construction has
been a rigid molecule. We have discovered that antiparallel DNA double crossover
molecules can provide this capability. We have incorporated
these components in DNA assemblies that make use of this rigidity
to achieve control on the geometrical level, as well as on the
topological level. Some of these involve double crossover
molecules, and others involve double crossovers associated with
geometrical figures, such as triangles and deltahedra.
This research has been supported by grants from the National
Institute of General Medical Sciences and the Office of Naval
Research.
*Corresponding Address:
Professor Nadrian C. Seeman, Department of Chemistry, New York
University, New York, NY 10003, USA
email: [email protected]
http://seemanlab4.chem.nyu.edu/homepage.html
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