Experimental phasing: Difference between revisions

Add CNS (shame on me for forgetting) and minor changes
(a first try)
(Add CNS (shame on me for forgetting) and minor changes)
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SHARP was the first "product" of [http://www.globalphasing.com/ Global Phasing], in the mid '90s. It was a spectacular improvement over existing methods and has been described in [http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B7CV2-4B432JN-DY&_user=3208271&_coverDate=12%2F31%2F1997&_alid=865881649&_rdoc=5&_fmt=high&_orig=search&_cdi=18066&_sort=d&_docanchor=&view=c&_ct=5&_acct=C000047720&_version=1&_urlVersion=0&_userid=3208271&md5=1a457e261908cb35b80cd39fc7c7cd6d Maximum-likelihood heavy-atom parameter refinement for multiple isomorphous replacement and multiwavelength anomalous diffraction methods].
SHARP was the first "product" of [http://www.globalphasing.com/ Global Phasing], in the mid '90s. It was a spectacular improvement over existing methods and has been described in [http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B7CV2-4B432JN-DY&_user=3208271&_coverDate=12%2F31%2F1997&_alid=865881649&_rdoc=5&_fmt=high&_orig=search&_cdi=18066&_sort=d&_docanchor=&view=c&_ct=5&_acct=C000047720&_version=1&_urlVersion=0&_userid=3208271&md5=1a457e261908cb35b80cd39fc7c7cd6d Maximum-likelihood heavy-atom parameter refinement for multiple isomorphous replacement and multiwavelength anomalous diffraction methods].
SHARP has been regularly improved since then, and the legendary 'week-long runs' now complete in a few minutes. Much has been argued about how SHARP implements Maximum Likelihood, and Phaser and BP3 claim to do better in SAD cases. SHARP does do really well for SAD phasing, but the main advantage still is the ability to describe very complicated experiments, involving multiple wavelengths, various crystals of the same derivative and various derivatives (all with or without anomalous data) in a very appropriate manner. All these can also be done through the autoSHARP pipeline as well.
SHARP has been regularly improved since then, and the legendary 'week-long runs' now complete in a few minutes. Much has been argued about how SHARP implements Maximum Likelihood, and Phaser and BP3 claim to do better in SAD cases. SHARP does do really well for SAD phasing, but the main advantage still is the ability to describe very complicated experiments, involving multiple wavelengths, various crystals of the same derivative and various derivatives (all with or without anomalous data) in a very appropriate manner. All these can also be done through the autoSHARP pipeline as well. The SHARP interface is web based, excellent on-line help, and very good examples. A CCP4i interface to SHARP is also available.


* [[http://solve.lanl.gov/Solve/solve.html|SOLVE SOLVE]]  
* [http://cns-online.org/v1.2/ CNS]
Maximum likelihood phasing in CNS appeared to my recollection shortly after SHARP and has a perfectly decent implementation that has solved many structures and produces excellent maps. It has an excellent web-based interface, good on-line help, and very good example scripts.
 
* [[http://solve.lanl.gov/Solve/solve.html SOLVE]]  


SOLVE was the first truly automated experimental phasing pipeline in the second half of the '90s. Its worth mentioning also in this section, since it uses a number of ingenious solutions to the phasing problem, e.g. correlated phasing, that produce phases of excellent quality and can easily be used just for phasing outside its own pipeline.
SOLVE was the first truly automated experimental phasing pipeline in the second half of the '90s. Its worth mentioning also in this section, since it uses a number of ingenious solutions to the phasing problem, e.g. correlated phasing, that produce phases of excellent quality and can easily be used just for phasing outside its own pipeline.
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