Nadrian C. Seeman: DNA, not Merely the Secret of Life
Department of Chemistry, New York University, New York, NY 10003, USA.
We build branched DNA species that can be joined using Watson-Crick base pairing to produce N-connected objects and lattices. We have used ligation to construct DNA topological targets, such as knots, polyhedral catenanes, Borromean rings and a Solomon's knot.
Nanorobotics is a key area of application. We have made robust 2-state and 3-state sequence-dependent programmable devices and bipedal walkers. We have constructed 2-dimensional DNA arrays with designed patterns from many different motifs. We have used DNA scaffolding to organize active DNA components. We have used pairs of 2-state devices to capture a variety of different DNA targets. We have constructed a molecular assembly line using a DNA origami layer and three 2- state devices, so that there are eight different states represented by their arrangements. We have demonstrated that all eight products can be built from this system. Recently, we connected the nanoscale with the microscale using DNA origami.
We have self-assembled a 3D crystalline array and reported its crystal structure to 4 Å resolution. We can use crystals with two molecules in the crystallographic repeat to control the color of the crystals. Rational design of intermolecular contacts has enabled us to improve crystal resolution to better than 3 Å. We can now do strand displacement in the crystals to change their color, thereby making a 3D-based molecular machine; we can visualize the presence of the machine by X-ray diffraction.
The use of DNA to organize other molecules is central to its utility. Earlier, we made 2D checkerboard arrays of metallic nanoparticles, and have now organized gold particles in 3D. Most recently, we have ordered triplex components and a semiconductor within the same lattice. Thus, structural DNA nanotechnology has fulfilled its initial goal of controlling the internal structure of macroscopic constructs in three dimensions. A new era in nanoscale control awaits us.
This research has been supported by the following grants to NCS: CHE-1708776, NSF EFRI-1332411 and CCF-1526650 from the NSF, RGP0010/2017 from Human Frontiers Science Program, DE-SC0007991 from the US Department of Energy (DOE) for DNA synthesis and partial salary support, and Grant GBMF3849 from the Gordon and Betty Moore Foundation.
What to do when your grant is rejected
Losing out on a grant hurts, but don’t lose heart — average success rates are around 20% among large funders, so grant rejection is common. Discover how to bounce back, find alternative funding and boost your chances of success next time.
Revolutionary cryo-EM is taking over structural biology
The number of protein structures being determined by cryo-electron microscopy is growing at an explosive rate. A report published by Nature on February 10, 2020 says that a revolutionary technique for determining the 3D shape of biomacromolecules is booming. Last week, a database that collects protein and other molecular structures determined by cryo-electron microscopy, or cryo-EM, acquired its 10,000th entry.
Registration for Advanced methods in macromolecular crystallization IX is now open
Proposed deadline for applications for this course which is focused on theoretical aspects of crystal growth process as well as practical work is March 20th 2020.
Instruct-ERIC Training call now open
Call for proposals for Instruct Centre Training Courses to be held in 2020 is now open.