Question

The term “electron density maps” is related to which of the following technique?

a) Optical microscopy
b) NMR spectroscopy
c) cryo-electron microscopy
d) X-ray crystallography​

Answer 1

Answer:

One bottleneck in high-throughput protein crystallography is interpreting an electron-density map, that is, fitting a molecular model to the 3D picture crystallography produces. Previously, we developed ACMI (Automatic Crystallographic Map Interpreter), an algorithm that uses a probabilistic model to infer an accurate protein backbone layout. Here, we use a sampling method known as particle filtering to produce a set of all-atom protein models. We use the output of ACMI to guide the particle filter's sampling, producing an accurate, physically feasible set of structures.

Answer 2

Answer:

In X-ray crystallography, a representation that resembles a geological survey map of planes drawn through a crystal. It shows contours of equal electron density surrounding the individual atoms: steeper around heavier atoms; more shallow around lighter atoms.