Dear Desmond, Chimera is for showing structures, but you have to input the structure data (similar to opening a document in Word). Luckily, there are some databases that include structures of DNA double helices. If Chimera is started, you can use File... Fetch by ID. Make sure it is set to the "PDB ID" option and enter an ID code for a DNA double helix structure (don't worry, I'll give you some examples in a moment). This will get the data file from the database over the web and open it in Chimera. There are actually lots of different structures of DNA double helices, but a few examples are: 158d 167d 1bna Again, you can look at any one of these by entering the code in the Fetch by ID dialog of Chimera and clicking the Fetch button. I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. meng@cgl.ucsf.edu UCSF Computer Graphics Lab and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco http://www.cgl.ucsf.edu/home/meng/index.html On Monday, April 4, 2005, at 05:16 PM, Desmond McMahon wrote:

I downloaded Chimera and I tried to understand the help section. I'm a high school student and i'm using this for a report. CAN YOU PLEASE PLEASE PLEASE tell me how to START a DNA/Double helix structure and I can't find out. Can you help me???   Desmond