Biomedical Engineering Reference
In-Depth Information
Fig. 8
Schematic representation of DNA junctions and crossover tiles. Motif 1 is
a branched DNA junction with three arms and motif 2 with four arms. Every termi-
nal in the arm is an unpaired ssDNA. The ssDNA acts as “sticky ends”, which may pair
with another complementary strand. The two motifs
3
and
4
are two different antiparal-
lel double-crossover molecules containing an even number of half-helical turns between
branch points (DAE) or an odd number (DAO). They are more stable and thus usually
applied. Oligonucleotide strands are individually represented with different colors
Fig. 9
Assembly of DNA junctions.
a
Four of the junctions in motif
2
are complexed to
yield the structure in motif
5
. The complex has maintained open valences so that it could
be extended by the addition of more monomers.
b
Square lattice formed from four-arm
junctions held in a square-planar configuration (
6
) by protein RuvA, with TEM image of
the lattice shown beneath. The
scale bar
represents 100 nm. Reprinted with permission
from [47].
c
1D self-assembly of the motif
7
derives into a railroad track-like array
8
,and
the 2D self-assembly produces a lattice array
9
.AnAFMimageofarray
9
is shown be-
neathwithascansizeof400
400 nm
2
. Adapted with permission from [45, 46]
×
of this quadrilateral contains further sticky ends so, in principle, this arrange-
ment could be extended to produce a lattice in two or three dimensions. As
showninmotif7inFig.9,suchjunctionsformarhomboidalsupramolecu-
lar structure [45, 46]. A set of rhomboids was subsequently assembled into
1D“railroadtracks”(motif8inFig.9)aswellasinto2Dlattices(motif9in
