Electron density modification methods are an indispensable part of any de novo macromolecular crystal structure determination and can be of crucial importance for determining structures solved by the molecular replacement method. In MAIN, a number of density modification procedures have been implemented. They encompass tools like solvent flattening and electron density averaging. In addition, maps can be generated using maximum likelihood weighting as well as by the “kick map” approach. Kick maps have been shown to be a good alternative to maximum-likelihood maps, when model bias has to be revealed. These approaches are intergrated with the MAIN model building and refinement tools, which also allow multicrystal averaging and refinement with non-crystallographic constraints across a variety of crystal forms.
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Turk, D. (2007). Density Modification In Main. In: Read, R.J., Sussman, J.L. (eds) Evolving Methods for Macromolecular Crystallography. NATO Science Series, vol 245. Springer, Dordrecht. https://doi.org/10.1007/978-1-4020-6316-9_10
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