Dear All,When we open either the mtz file or the mrc file by coot, we can rely on the contour level of the map (in the Map Settings of the Display Manager of the coot) to vary the thickness of the map.For peptide build by coot based on the crystal mtz file, if the contour level of the map is too low (for example absolute contour level less than 0.1, is this the correct threshold value to distinguish between acceptable and unacceptable mtz file for peptide rebuild based on crystal mtz file?), we will regard the quality of the mtz file is too low for the peptide build purpose, and the peptide build based on the too low contour level map would be regrded as not necessarily correct.However I find if I open a mrc file (electrnic microscopy density map)by coot, even the part of the map not for the peptide build, the common absolute contour level is about 0.05 (The default absolute contour level of the crystal mtz file is 0.3).Do you think the significant diffrence of the absolute contour level is caused by the diffrence of the mtz file and the mrc file,or caused by the low quality of the mrc file?If the default absolute contour level of the mrc file is really about 0.05, then how mush should be the acceptable level of absolute contour level of the mrc file for peptide build by coot?I am looking forward to getting your reply.Smith
