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Re: model_refinement



Forwarding to list.

----- Forwarded message from Denis Volkov <> -----

Date: Mon, 8 Sep 2003 17:41:54 +0400
From: Denis Volkov <>
To: Modeller Caretaker <>
Subject: Re: Fwd: Re: model_refinement

Hello Modeller,

Thursday, September 04, 2003, 12:16:20 AM, you wrote:

MC> ----- Forwarded message from Oliver Hucke <> -----

MC> Date: Tue, 02 Sep 2003 10:03:00 -0700
MC> From: Oliver Hucke <>
MC> To: Modeller Care <>
MC> Subject: Re: model_refinement

MC> Hi Denis,

MC> did you compare the quality of the structure calculated with modeller 
MC> with that of the template(s)?
MC> If the quality of the model is really worse something might be wrong 
MC> with your alignment. Did you do the manual adjustment of the input 
MC> alignment on basis of the analysis of the quality of the first models? 
MC> This usually helps a lot.
MC> I do not think that it is necessary to use charmm or another external 
MC> molecular mechanics package to improve the quality of your model. 
MC> Modeller actually uses (an older version of) the charmm force field for 
MC> the molecular mechanics part of the optimization.

MC> Best,
MC> Oliver

MC> Modeller Care wrote:

>>------ Forwarded Message
>>
>>From: Denis Volkov <>
>>X-Mailer: The Bat! (v1.52f)
>>Reply-To: Denis Volkov <>
>>X-Priority: 3 (Normal)
>>Message-ID: <>
>>To: modeller <>
>>Subject: model_refinment
>>
>>
>>Hello everyone,
>>I successfully used Modeller to model unknown protein. Now I'd like
>>to sent my model to Protein Data Bank. So i checked my structure
>>using Procheck and find some problems, namely some bad contacts,etc.
>>In order to clean a structure i used Charmm program for energy
>>minimization. But after it i obtain structure with bad angles and
>>bond lengths. Can anybody know how to clean a structure well for
>>PDBank and what programs should be use for it.
>>Thanks in advance
>>Denis Volkov
>>
>>Enzyme Laboratory,IBCH RAS
>> 
>>
>> 
>>


Hello,Oliver
Thank you for fast answering! :)
No i didn't test a quality of templates course i used 4 structures
as a templates so its difficult to do it. Alignment I manually adjust
so it's not a origin of fault. I look at the model again and think
it's not so bad as I said. But a problem is more global:
A similarity with templates is no more than 20%. A great deal of
mismatches are in loop origin so it's not so bad...but can i do a good
model with so low similarity? As I said I use Charmm, I used it  to investigate
protein-protein interactions. I used Modeller model to investigate
enzyme-substrate and enzyme-inhibitor interaction. But after MD a
structure was a great deal disturbed. Is it a problem of low
similarity or as you said its not good to use MD with models maid by
Modeller?

Also I've another question: earlier I used Windows version of
Modeller and everything was OK, but now I run Modeller on Linux and
have some problem. When I used sequence-search routine it runs for
some time (~30-40 min) but then terminated. In log file there is
nothing interesting: chains libraries were opened two times. First
times it takes 20Mb of memory, second time ~200 Mb and then it
terminated. So the problem is a memory usage as I think. I looked
through archive and find out that it's a common problem. I checked my
top-files and system config (stack size) and everything is good. I've
got 500 Mb RAM but half of it utilized by X-Windows. So may be i
should run some Modeller routines without running X ?

Thanks in advance
Denis Volkov

Enzyme Laboratory,IBCH RAS
-- 
Best regards,
 Denis                            ">mailto:

----- End forwarded message -----