But, if you convert to structure factors and recalculate the map in a different cell, the features will be "stretched" to fill the cell, which I take it is the original problem.
I found Kleywegt's RAVE package very convenient for doing this, but i believe the functionality is now available in ccp4 mapmask and maprot programs. The Phaser Wiki has a page with instructions for cutting out electron density within a mask, and putting it in a large P1 cell for use as a molecular replacement model. Perhaps you could modify that to achieve your aims. http://www.phaser.cimr.cam.ac.uk/index.php/Using_Electron_Density_as_a_Model eab On 05/20/2014 03:07 AM, herman.schreu...@sanofi.com wrote:
Dear Niu, Provided you have a complete asymmetric unit (unit cell in P1), you could also convert this map to structure factors and manipulate those, e.g. with sftools. To calculate structure factors you could use sfall and also clipper has utilities to convert a map to structure factors. Best, Herman *Von:*CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] *Im Auftrag von *Niu Tou *Gesendet:* Montag, 19. Mai 2014 23:25 *An:* CCP4BB@JISCMAIL.AC.UK *Betreff:* [ccp4bb] map manipulation questions Dear All, I have a ccp4 format map file in P1 spacegroup, I would like to manipulate it in several ways: 1. enlarge the cell dimension . When I tried "CELL" keyword in MAPMAN, the density scaled up together with the cell dimension. Does anybody know how to do it without changing the density? 2. Change the space group to P2. 3. Move the density away from its original place, i.e. apply a translocation vector to it. Does anybody know the answers? Thanks in advance! Regards, Niu
