On Sep 20, 2008, at 2:18 PM, Jayashankar wrote:
> Dear friends and crystallographers,
Are they mutually exclusive?
>
>
> During One of my lab meeting ,
>
> I told twinning in crystals are ok, because ccp4's recent releases
> just need
> the keyword TWIN to solve them,
I believe the closer you get to complete twinning, the more
intractable the problem gets. I don't know if the pain scales linearly
with twinning fraction.
>
>
> As a new generation research student, I am now confused,
This is both normal and proper, but has nothing to do with generation.
> is that I need to
> learn and understand all programs(so many...but research does not
> mean
> relaying on them)
> to solve my crystallographic problems(is that all)....
> if you see all the queries in ccp4BB is just about undocumented or
> misunderstood program oriented questions.
Actually there are many lively discussions about fundamental
problems. These will often arise in the context of a specific
program, but you still have to understand the problem the program is
designed to solve.
>
>
> is that all i have to learn in crystallography in future.
That's up to you, but I would say no. Learn the fundamentals.
Programs will come and go.
>
> Still upto what limitations we are now in crystallography.
> this is my very naive and prime question.
>
> 1.Phase problem
This is still "the" problem. Some inroads have been made toward ab
initio solutions, but the traditional heavy-atom methods, variations
like MAD phasing, and molecular replacement remain in practice the
standard approaches for what you usually find in the PDB.
>
> 2.twin problem
see above.
>
> 3.solving intrinsically disordered proteins
Crystals give a spatial average, so there is nothing magical you can
do to overcome intrinsic disorder.
>
> 4.hetro multimeric proteins
ribosomes are I think the current upper bound
>
> 5.high order oligomers
Chromatin fibers maybe?
>
> 6.cryo crystallography
This is routine.
>
> 7.automation in high through put crystallography
The main problem is finding strong enough amphetamines to keep one
awake while reading the papers.
>
> 8.radiation damage
see cryocrystallography, and take lots of vitamin C
>
> 9.kinetic crystallography
Laue? There is now a fair body of work, but development for
irreversible enzyme systems is probably a worthwhile future goal.
>
> 10. crystal growth research (antigravity, pressure )
Anti-gravity?
>
> 11.stereo graphics
In the land of the blind, the one-eyed Macintosh user is king (as long
as the program is not X-windows-based).
>
>
> if i am right all the above has been studied (....what we are not
> clear
> still about them),
>
> I need an answer to motivate me in doing my research in
> Crystallography.
>
> S.Jayashankar
> (A confused new generation research student)
> Research Student
> Institute for Biophysical Chemistry
> Hannover Medical School
> Germany.
|