Most X-ray crystallography analyses are now performed at centralized government labs that provide…

Most X-ray crystallography analyses
are now performed at centralized government labs that provide high-powered
X-ray beams, which are able to resolve electron densities better than what can
be done with smaller institutional instruments, and without the high costs of
maintaining an in-house facility. However, even with this improved data
collection methodology, the rate-limiting step in X-ray crystallography is
often the ability to grow diffractable crystals.

a. If a protein of interest is not
amenable to crystallization, even after testing a large number of buffer
conditions and
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Most X-ray crystallography analyses
are now performed at centralized government labs that provide high-powered
X-ray beams, which are able to resolve electron densities better than what can
be done with smaller institutional instruments, and without the high costs of
maintaining an in-house facility. However, even with this improved data
collection methodology, the rate-limiting step in X-ray crystallography is
often the ability to grow diffractable crystals.

a. If a protein of interest is not
amenable to crystallization, even after testing a large number of buffer
conditions and temperatures, what is the most likely explanation? b. What are
some of the advantages and disadvantages of obtaining diffractable protein
crystals using an orthologous protein from another species? c. If no suitable
orthologous proteins were available, how might you modify the protein of
interest to increase your chances of obtaining diffractable crystals? d. If
none of these alternative approaches result in the isolation of diffractable
crystals, what other method could possibly be used to obtain the molecular
structure of your protein? What is the primary advantage and disadvantage of
this other method relative to X-ray crystallography?

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