Which of the following detector is used for data collection in protein crystallography?
Routine protein crystallography is commonly performed using an image plate, a multi-wire or a ccd area detector. The phosphors used with ccd area detectors are somewhat more sensitive for Mo Kα than for Cu Kα radiation.
What are the different types of crystallography?
Crystallography & Types of Crystals
- Isometric. This system comprises crystals with three axes, all perpendicular to one another and all have equal length.
- Formation of Crystals.
What is the process of crystallography?
X-ray crystallography is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. In a single-crystal X-ray diffraction measurement, a crystal is mounted on a goniometer.
What is molecular replacement in crystallography?
Molecular replacement is fundamentally a simple trial-and-error method of solving crystal structures when a suitable related model is available. The underlying simplicity of the method is often obscured by the mathematical trickery required to make the searches computationally tractable.
What is completeness in crystallography?
Completeness of data can be defined by the number of collected crystallographic reflections in comparison to the number of theoretically possible reflections unique for the given crystal symmetry.
What is the most common method of solving the phase problem in protein crystallography?
The most common approach to this problem has been multiple isomorphous replacement (MIR) (Green et al., 1954). Figure 3 Each reflection in the diffraction pattern can be described as a wave with a certain magnitude and phase.
How does NMR determine protein structure?
NMR involves the quantum-mechanical properties of the central core (“nucleus”) of the atom. This information can be used to determine the distance between nuclei. These distances in turn can be used to determine the overall structure of the protein.
What are its different elements of crystallography?
These are the cubic, tetragonal, orthorhombic, monoclinic, triclinic, trigonal and hexagonal.
What are the elements of crystallography?
Chapter 1: Elements of Crystallography
- Unit Cell.
- Crystallographic Directions and Planes.
- Hexagonal Indices.
- The Stereographic Projection and the Standard Projection.
- Further readings.
What is the phase problem in crystallography?
In physics, the phase problem is the problem of loss of information concerning the phase that can occur when making a physical measurement. The name comes from the field of X-ray crystallography, where the phase problem has to be solved for the determination of a structure from diffraction data.
What is the purpose of molecular replacement?
The term ‘molecular replacement’ (MR) is generally used to describe the use of a known molecular model to solve the unknown crystal structure of a related molecule.