Dear all,
I have some basic queries regarding modeller working & its performance.
1) What is the accuracy of model building by modeller?
2) I have read in the modeller mailing list that in the case of multiple templates, modeller uses weighted sum over all the templates. Does this mean that spatial restraints are derived individually from the alignment between first template & query sequence and from the alignment between the second template & the query sequence? Then these resraints are added and weights are applied to that template according to the local similarity with the query sequence? Anyone please correct me if I am wrong?
3) I have built a model using 2 templates with modeller9v2. RMSD (only backbone atoms) between the model & the first template is 1.6 ang & with second is 3.3. Sequence identity is higher between the target sequence & first template as compared to that of the second template. How can I calculate the accuracy of this model in terms of percentage? What is the way of calculating the accuracy of model building?
Looking forward to your reply? Kindly reply and enhance my knowledge.
Thanks in advance
Ruchi
rsachdeva@imtech.res.in wrote: > 1) What is the accuracy of model building by modeller?
There is no way to tell, of course, without determining the structure experimentally and comparing it to the model. Model assessment methods can give you an idea (or the sequence identity is a crude guide).
> 2) I have read in the modeller mailing list that in the case of multiple > templates, modeller uses weighted sum over all the templates. Does this mean > that spatial restraints are derived individually from the alignment between > first template & query sequence and from the alignment between the second > template & the query sequence? Then these resraints are added and weights are > applied to that template according to the local similarity with the query > sequence? Anyone please correct me if I am wrong?
No. Each restraint (say, for example, a given Calpha-Calpha distance restraint) incorporates information from all templates. Refer to the Modeller 93 paper for full information.
Ben Webb, Modeller Caretaker
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Modeller Caretaker
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rsachdevaļ¼ imtech.res.in