Try here: http://www.ebi.ac.uk/pdbe/emdb/ You can (if you get the EM map) play around with various programs and manipulate the level until the mask matches the molecular weight of your object of interest. Or contact the authors of the EM map. Ask for either CCP4 format map or MRC, you can use programs from the USF suite to inter convert between the formats. If they used EMAN then most likely the CCP4 format is still bogus but MRC works fine.
Jürgen On Jun 2, 2011, at 5:24 PM, Hailiang Zhang wrote: Hi, I am trying to compare a published EM map with X-ray map in hand, and have several questions: 1. EM map seldom indicates the sigma level, and it was said because of the box size uncertainty during EM model construction. Now, I wonder is there any way we can sort of its equivalent sigma level to X-ray map? 2. The EM structure deposited in pdb don't have any experimental data, and not sure how to obtain them and generate the map file. Sorry if this is wrong place to post EM questions. Hailiang ...................... Jürgen Bosch Johns Hopkins Bloomberg School of Public Health Department of Biochemistry & Molecular Biology Johns Hopkins Malaria Research Institute 615 North Wolfe Street, W8708 Baltimore, MD 21205 Phone: +1-410-614-4742 Lab: +1-410-614-4894 Fax: +1-410-955-3655 http://web.mac.com/bosch_lab/
