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Re: [modeller_usage] question about unusual bond length, bond angle, Chirality deviations



First of all, thanks for reply. I don't know many things about homology modeling. 
I did homology modelling for dimer. 
Modeller found the template for MJ0305(model) as 1ots.pdb.  The fasta sequence length of template(1ots.pdb) is 466, and the fasta sequence length of model (MJ0305) is 396. According to the Modeller, the sequence identity between model and template is 24%.

After alignment, I used loop patch to generate the model. I thought using loop modelling gives more accurate structure for homology modelling. When I checked model pdb structure, it gave the warning message "unusual bond length, bond angle, Chirality deviations". 
I think this error comes from 70 fasta sequence length difference between model and template as suggested from Modeller Caretaker. 

My question:
In order to generate best model from Modeller, which residues of template should I delete? 
 (I heard that the limit of Modeller is about 15 residues from last email). My current sequence difference is 70, so I should delete some residues.

My attached my code, outputs to explain my situation...

1. align2d.py  ---> output: MJ0305-1otsAB.ali, MJ0305-1otsAB.pap  // alignment
2. model-loop.py                                                                                  //  loop modeling
    after loop modeling, I got pdb structure for model. 

Thanks so much...

Sincerely
Hyun.

************************** Fasta sequence *********************************************
Template:   (1ots.pdb)  
MKTDTPSLETPQAARLRRRQLIRQLLERDKTPLAILFMAAVVGTLVGLAAVAFDKGVAWLQNQRMGALVHTADNYPLLLTVAFLCSAVLAMFGYFLVRKYAPEAGGSGIPEIEGALEDQRPVRWWRVLPVKFFGGLGTLGGGMVLGREGPTVQIGGNIGRMVLDIFRLKGDEARHTLLATGAAAGLAAAFNAPLAGILFIIEEMRPQFRYTLISIKAVFIGVIMSTIMYRIFNHEVALIDVGKLSDAPLNTLWLYLILGIIFGIFGPIFNKWVLGMQDLLHRVHGGNITKWVLMGGAIGGLCGLLGFVAPATSGGGFNLIPIATAGNFSMGMLVFIFVARVITTLLCFSSGAPGGIFAPMLALGTVLGTAFGMVAVELFPQYHLEAGTFAIAGMGALLAASIRAPLTGIILVLEMTDNYQLILPMIITGLGATLLAQFTGGKPLYSAILARTLAKQEAEQLARSK

Model: (Y305_METJA,    Uncharacterized protein MJ0305 )
MPMNIVNMFGKYIKIIKWIGIASLIGIVGGLSSVIIAIIIEYFPEKHNVLLIPIVFFIAGLFVDYIYELKGSGIDRVLKALNTNEKLTWIRGLLKVLLAGAVIAVGGSAGKEGPCVQSSASFADELYRLLKLKNRELVIITGIAGGLGGAFSAPLGTAILACEIIEHENFNYINLIPPIIASVVGYLIFYLITGRKHLFNITLSYTINIHDFLLFILGAFFCSLIAHCYIKTYRKISSTFDNLKIPYCIKTLIGGILVAVISYFIPEVMGMGLTLTKELFIMEFSLVFLVLLLIGKILATSFTVGSGTPGGLVFPSMCIGAISGIIFGSLIGDCSAPYIVLGIATTLSATTNAPLGGAVLCTEIFGFDFAVPASIGAVIGYQMTKLETIFKYIRF

**************************************align2d.py*********************************************************
from modeller import *

env = environ()
aln = alignment(env)
mdl = model(env, file='1ots', model_segment=('FIRST:A','LAST:B'))
aln.append_model(mdl, align_codes='1otsAB', atom_files='1ots.pdb')
aln.append(file='MJ0305.ali', align_codes='MJ0305')
aln.align2d()
aln.write(file='MJ0305-1otsAB.ali', alignment_format='PIR')
aln.write(file='MJ0305-1otsAB.pap', alignment_format='PAP')

*****************************model-loop.py***************************************************************
# Homology modeling by the automodel class
from modeller import *
from modeller.automodel import *    # Load the automodel class

log.verbose()
env = environ()

# directories for input atom files
env.io.atom_files_directory = ['.', '../atom_files']

a = loopmodel(env,
              alnfile  = 'MJ0305-1otsAB.ali',     # alignment filename
              knowns   = '1otsAB',              # codes of the templates
              sequence = 'MJ0305')              # code of the target
a.starting_model= 1                 # index of the first model
a.ending_model  = 1                 # index of the last model
                                    # (determines how many models to calculate)
a.md_level = None                   # No refinement of model

a.loop.starting_model = 1           # First loop model
a.loop.ending_model   = 50           # Last loop model
a.loop.md_level       = refine.fast # Loop model refinement level

a.make()     

************************** MJ0305-1otsAB.ali **********************************************
>P1;MJ0305
sequence:MJ0305:     : :     : :::-1.00:-1.00
--------------MPMNIVNMFGKYIKIIKWIGIASLIGIVGGLSSVIIAII--IEYFPEKHNVLLI-PIVFFI
AGLFV--DYIYELKGSGIDRVLKALNTNEKLTWIRGLLKVLLAGAVIAVGG-SAGKEGPCVQSSASFADELYRLL
KLK---NRELVIITGIAGGLGGAFSAPLGTAILACEIIEHENFNYINL-IPPIIASVVGYLIFYLITGRK-HLFN
I-TLSYTINIHDFLLFILGAFFCSLIAHCYIKTYRKISSTFDNLKIPYCIK-TLIGGI---LVAVISYFIPEVMG
MGLTLTKELFIMEFSLVFLVLLLIGKILATSFTVGSGTPGGLVFPSMCIGAISGIIFGSLIG-------DCSAPY
IVLGIATTLSATTNAPLGGAVLCTEIFG-FDFAVP---ASIGAVIGYQMTKLETIFKYIRF/MPMN---------
--IVNMFGKYIKIIKWIGIASLIGIVGGLSSVIIAIIIEYF-PEKHNVL---------LIPIVFF---IA---GL
FV--DYIYELKGSGIDRVLKALNTNEKLTWIRGLLKVLLAGAVIAVGG-SAGKEGPCVQSSASFADELYRLLKLK
---NRELVIITGIAGGLGGAFSAPLGTAILACEIIEHENFNYINL-IPPIIASVVGYLIFYLITGRK-HLFNI-T
LSYTINIHDFLLFILGAFFCSLIAHCYIKTYRKISSTFDNLKIPYCIK-TLIGGI---LVAVISYFIPEVMGMGL
TLTKELFIMEFSLVFLVLLLIGKILATSFTVGSGTPGGLVFPSMCIGAISGIIFGSLIG-------DCSAPYIVL
GIATTLSATTNAPLGGAVLCTEIFG-FDFAVP---ASIGAVIGYQMTKLETIFKYIRF--------*

>P1;1otsAB
structureX:1ots.pdb:  17 :A:+885 :B:MOL_ID  1; MOLECULE  VOLTAGE-GATED CLC-TYPE CHLORIDE CHANNEL ERIC; CHAIN  A, B; ENGINEERED  YES; MOL_ID  2; MOLECULE  FAB FRAGMENT (HEAVY CHAIN); CHAIN  C, E; MOL_ID  3; MOLECULE  FAB FRAGMENT (LIGHT CHAIN); CHAIN  D, F:MOL_ID  1; ORGANISM_SCIENTIFIC  ESCHERICHIA COLI; ORGANISM_COMMON  BACTERIA; GENE  ERIC OR B0155; EXPRESSION_SYSTEM  ESCHERICHIA COLI; EXPRESSION_SYSTEM_COMMON  BACTERIA; EXPRESSION_SYSTEM_STRAIN  BL21DE3; EXPRESSION_SYSTEM_VECTOR_TYPE  PLASMID; EXPRESSION_SYSTEM_PLASMID  PET28B+; MOL_ID  2; ORGANISM_SCIENTIFIC  MUS MUSCULUS; ORGANISM_COMMON  MOUSE; CELL_LINE  HYBRIDOMA CELL LINE; MOL_ID  3; ORGANISM_SCIENTIFIC  MUS MUSCULUS; ORGANISM_COMMON  MOUSE; CELL_LINE  HYBRIDOMA CELL LINE: 2.51:-1.00
RRRQLIRQLLERDKTPLAILFMAAVVGTLVGLAAVAFDKGVAWLQNQRMGALVHTADNYPLLLTVAFLCSAVLAM
FGYFLVRKYAPEAGGSGIPEIEGALEDQRPVRWWRVLPVKFFGGLGTLGGGMVLGREGPTVQIGGNIGRMVLDIF
RLKGDEARHTLLATGAAAGLAAAFNAPLAGILFIIEEMRPQ-FRYTLISIKAVFIGVIMSTIMYRIFNHEVALID
VGKLS-DAPLNTLWLYLILGIIFGIFGPIFNKWVLGMQDLLHRVHGGNITKWVLMGGAIGGLCGLLGFVAPATSG
GGFNLIPIATAGNFSMGMLVFIFVARVITTLLCFSSGAPGGIFAPMLALGTVLGTAFGMVAVELFPQYHLEAGTF
AIAGMGALLAASIRAPLTGIILVLEMTDNYQLILPMIITGLGATLLAQFTGGKPLYSAILA-RTLAKQEAEQ/RR
QLIRQLLERDKTPLAILFMAAVVGTLVGLAAVAFDKGVAWLQNQRMGALVHTADNYPLLLTVAFLCSAVLAMFGY
FLVRKYAPEAGGSGIPEIEGALEDQRPVRWWRVLPVKFFGGLGTLGGGMVLGREGPTVQIGGNIGRMVLDIFRLK
GDEARHTLLATGAAAGLAAAFNAPLAGILFIIEEMRPQ-FRYTLISIKAVFIGVIMSTIMYRIFNHEVALIDVGK
LS-DAPLNTLWLYLILGIIFGIFGPIFNKWVLGMQDLLHRVHGGNITKWVLMGGAIGGLCGLLGFVAPATSGGGF
NLIPIATAGNFSMGMLVFIFVARVITTLLCFSSGAPGGIFAPMLALGTVLGTAFGMVAVELFPQYHLEAGTFAIA
GMGALLAASIRAPLTGIILVLEMTDNYQLILPMIITGLGATLLAQFTGGKPLYSAILARTLAKQEA*


************************** MJ0305-1otsAB.pap **********************************************
 _aln.pos         10        20        30        40        50        60
1otsAB    RRRQLIRQLLERDKTPLAILFMAAVVGTLVGLAAVAFDKGVAWLQNQRMGALVHTADNYPLLLTVAFL 
MJ0305    --------------MPMNIVNMFGKYIKIIKWIGIASLIGIVGGLSSVIIAII--IEYFPEKHNVLLI 
 _consrvd                *  *  *             *   *          *        *    *

 _aln.p   70        80        90       100       110       120       130
1otsAB    CSAVLAMFGYFLVRKYAPEAGGSGIPEIEGALEDQRPVRWWRVLPVKFFGGLGTLGGGMVLGREGPTV 
MJ0305    -PIVFFIAGLFV--DYIYELKGSGIDRVLKALNTNEKLTWIRGLLKVLLAGAVIAVGG-SAGKEGPCV 
 _consrvd    *    * *    *  *  ****     **       * * *      *     **   * *** *

 _aln.pos  140       150       160       170       180       190       200
1otsAB    QIGGNIGRMVLDIFRLKGDEARHTLLATGAAAGLAAAFNAPLAGILFIIEEMRPQ-FRYTLISIKAVF 
MJ0305    QSSASFADELYRLLKLK---NRELVIITGIAGGLGGAFSAPLGTAILACEIIEHENFNYINL-IPPII 
 _consrvd *              **    *     ** * **  ** ***       *      * *    *

 _aln.pos    210       220       230       240       250       260       270
1otsAB    IGVIMSTIMYRIFNHEVALIDVGKLS-DAPLNTLWLYLILGIIFGIFGPIFNKWVLGMQDLLHRVHGG 
MJ0305    ASVVGYLIFYLITGRK-HLFNI-TLSYTINIHDFLLFILGAFFCSLIAHCYIKTYRKISSTFDNLKIP 
 _consrvd   *    * * *      *     **         *                *

 _aln.pos      280       290       300       310       320       330       340
1otsAB    NITKWVLMGGAIGGLCGLLGFVAPATSGGGFNLIPIATAGNFSMGMLVFIFVARVITTLLCFSSGAPG 
MJ0305    YCIK-TLIGGI---LVAVISYFIPEVMGMGLTLTKELFIMEFSLVFLVLLLIGKILATSFTVGSGTPG 
 _consrvd    *  * **    *        *   * *  *        **   **         *     ** **

 _aln.pos        350       360       370       380       390       400
1otsAB    GIFAPMLALGTVLGTAFGMVAVELFPQYHLEAGTFAIAGMGALLAASIRAPLTGIILVLEMTDNYQLI 
MJ0305    GLVFPSMCIGAISGIIFGSLIG-------DCSAPYIVLGIATTLSATTNAPLGGAVLCTEIFG-FDFA 
 _consrvd *   *    *   *  **                    *    * *   *** *  *  *

 _aln.p  410       420       430       440       450       460       470
1otsAB    LPMIITGLGATLLAQFTGGKPLYSAILA-RTLAKQEAEQ/RRQLIRQLLERDKTPLAILFMAAVVGTL 
MJ0305    VP---ASIGAVIGYQMTKLETIFKYIRF/MPMN-----------IVNMFGKYIKIIKWIGIASLIGIV 
 _consrvd  *      **    * *        *                  *                *   *

 _aln.pos  480       490       500       510       520       530       540
1otsAB    VGLAAVAFDKGVAWLQNQRMGALVHTADNYPLLLTVAFLCSAVLAMFGYFLVRKYAPEAGGSGIPEIE 
MJ0305    GGLSSVIIAIIIEYF-PEKHNVL---------LIPIVFF---IA---GLFV--DYIYELKGSGIDRVL 
 _consrvd  **  *                *         *    *         * *    *  *  ****

 _aln.pos    550       560       570       580       590       600       610
1otsAB    GALEDQRPVRWWRVLPVKFFGGLGTLGGGMVLGREGPTVQIGGNIGRMVLDIFRLKGDEARHTLLATG 
MJ0305    KALNTNEKLTWIRGLLKVLLAGAVIAVGG-SAGKEGPCVQSSASFADELYRLLKLK---NRELVIITG 
 _consrvd  **       * * *      *     **   * *** **              **    *     **

 _aln.pos      620       630       640       650       660       670       680
1otsAB    AAAGLAAAFNAPLAGILFIIEEMRPQ-FRYTLISIKAVFIGVIMSTIMYRIFNHEVALIDVGKLS-DA 
MJ0305    IAGGLGGAFSAPLGTAILACEIIEHENFNYINL-IPPIIASVVGYLIFYLITGRK-HLFNI-TLSYTI 
 _consrvd  * **  ** ***       *      * *    *      *    * * *      *     **

 _aln.pos        690       700       710       720       730       740
1otsAB    PLNTLWLYLILGIIFGIFGPIFNKWVLGMQDLLHRVHGGNITKWVLMGGAIGGLCGLLGFVAPATSGG 
MJ0305    NIHDFLLFILGAFFCSLIAHCYIKTYRKISSTFDNLKIPYCIK-TLIGGI---LVAVISYFIPEVMGM 
 _consrvd       *                *                  *  * **    *        *   *

 _aln.p  750       760       770       780       790       800       810
1otsAB    GFNLIPIATAGNFSMGMLVFIFVARVITTLLCFSSGAPGGIFAPMLALGTVLGTAFGMVAVELFPQYH 
MJ0305    GLTLTKELFIMEFSLVFLVLLLIGKILATSFTVGSGTPGGLVFPSMCIGAISGIIFGSLIG------- 
 _consrvd *  *        **   **         *     ** ***   *    *   *  **

 _aln.pos  820       830       840       850       860       870       880
1otsAB    LEAGTFAIAGMGALLAASIRAPLTGIILVLEMTDNYQLILPMIITGLGATLLAQFTGGKPLYSAILAR 
MJ0305    DCSAPYIVLGIATTLSATTNAPLGGAVLCTEIFG-FDFAVP---ASIGAVIGYQMTKLETIFKYIRF- 
 _consrvd          *    * *   *** *  *  *         *      **    * *        *

 _aln.pos    890
1otsAB    TLAKQEA 
MJ0305    ------- 
 _consrvd

________________________________________
From: Modeller Caretaker []
Sent: Monday, March 29, 2010 2:26 PM
To: Song, Hyundeok (songhk)
Cc: 
Subject: Re: [modeller_usage] question about unusual bond length, bond angle, Chirality deviations

On 03/27/2010 07:26 PM, Song, Hyundeok (songhk) wrote:
> I generated the dimer by Modeller.
> Fasta sequence number of model(400) is 70 less than Fasta sequence
> number of template(470).
> Sequence identity between template and model is 24%.

If I understand you correctly, you have a loop that is about 70 residues
long. There's no way Modeller will be able to accurately model that (the
limit is about 15 residues). I can't tell for sure without seeing your
alignment file though.

> after selecting the template, I aligned them, and then I did loop
> modeling. (I attached the code at the bottom.) Finally I got final pdb
> structure, but when I checked my model, I found the below warning message.
>
> "Unusual bond length, unusual bond angle, Chirality deviations "

Looks from your script like you built 50 loops, so you can check the
other 49 PDB files to see if another loop looks better. But if your
loops are really 70 residues long, Modeller won't be able to help you.
Your best bet there is simply to remove those 70 residues from your
model sequence, and build a model of part of the protein.

        Ben Webb, Modeller Caretaker
--
             http://www.salilab.org/modeller/
Modeller mail list: http://salilab.org/mailman/listinfo/modeller_usage