Hi Aaron, TLSMD server suggests you possible optimal selections for TLS groups. If I remember correctly, it gives you a list of 20 options or so. It's up to you which one to choose. Usually you look at the graphic "residual vs number_of_tls_groups" and see at which point the curve stops dropping sharply. Also, you need to use common sense too, say, I wouldn't choose a set of TLS groups that brakes a helix into multiple parts. I'm actually puzzled about how that happened. I think it is a good question for Ethan Merritt, the author of TLSMD tool. Also, you may want to try a few possible TLS separations and see which one gives your better refinement results. Pavel. On 1/20/10 1:38 PM, Bart, Aaron G wrote:
Greetings everyone, I am still fairly new to crystallography, so forgive me for my naivety.
My question involves how the TLSMD server segments my protein and the effects it has on refinement. For instance when i use "Multi-Chain Alignment Analysis", which lines the sequence for all of my chains (a total of 12) and shows how TLS groups are divided among them, it shows varying selections of TLS groups among the different chains. It should be noted that the sequence is the same for all the chains in my protein.
Also if a TLS group splits a alpha helix into multiple parts, would this be valid? I have come to understand that helices move more like rigid bodies than segmented groups...
Thanks!
-Aaron _______________________________________________ phenixbb mailing list [email protected] http://phenix-online.org/mailman/listinfo/phenixbb