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Non-Canonical Peptides

Molfile to params creating invalid params output

Category: 
Non-Canonical Peptides

Hi, 

I am trying to generate a ncAA. My current workflow is using a program called iQmol which has a connection to a QChem server, to produce an appropriate mol file. I then use mol_file_to_params.py to get the params files. It creates a params file with all the atoms quite close together. Running mol_file_to_params gives me this output with the attached files:

 

edanhabel@Edans-MacBook-Pro-2 molfile2params % python molfile_to_params.py iqmol_pymol_aromatic.mol2 -n f5p --clobber --amino-acid PHE

Post Situation: 

NCAA attached at two points

Category: 
Non-Canonical Peptides

Hello,

I am trying to parameterize an NCAA which is a result of cyclization of the backbone, rather than just a PTM of an R group. I am using the molfile_to_params_polymer.py script (BTW is there a python 3 version of this script?) 

The connection points are at the R group of one residue, though there is a break in the chain (C=O -> C-OH) then a connection point to the nitrogen backbone atom of the subsequent residue.

When I use fixbb to modify to this residue I am getting the error:

Post Situation: 

adding NCAA to the N-terminal of RCSB pdb

Category: 
Non-Canonical Peptides

Hello,

I usually use my NCAAs by mutation in the sequences. 

Now, I am looking for a way or application in Rosetta to add, not mutation, NCAAs to the N- terminal and C- terminal of the sequences. 

The RCSB pdb starts with leu at N- terminal in attached picture that we need to add pyroglutamate before that 

 I wonder if anyone could let me know how I can add pyroglutamate using params file and rotlib file to the sequence. 

Post Situation: 

Patch to impose tetrahedral geometry on backbone O atom

Category: 
Non-Canonical Peptides

Hello,

I want to model the tetrahedral transition state of an enzyme where serine OG attacks the peptide backbone C atom. In this case the bond order of the backbone C=O bond changes to C-O(H) and the C-O(H) is not in plane anymore.

So far I wrote this patch file and added a hydrogen to the O atom in the input model which is named H01. The patch file is used since I get an error when I don't include it.

 

BEGIN_CASE

BEGIN_SELECTOR
NAME3 LEU
END_SELECTOR

Post Situation: 

params file for beta-amino acids

Category: 
Non-Canonical Peptides

Hi all,

I've been trying to insert a beta-amino acid into peptide, let's say, beta-homo-leucine. It seems that a params file for beta-hLeu is needed. Unforutnately, there is no params file for beta-hLeu in database in Rosetta, and molfile_to_params.py only works for alpha-amino acid. I've also visited https://rosie.rosettacommons.org/documentation/beta_peptide_design, but did't find helpful solution. So my question is:

Post Situation: 

NCAA Rotamers for Cyclosporin

Category: 
Non-Canonical Peptides

Hi, 

I'm using cyclosporin to as a test case for understanding the design of macrocycles using Rosetta.  In the $ROSETTA3_DB/chemical/residue_type_sets/fa_standard/residue_types/cyclosporin directory there are parameters for two cyclosporin specific residues.  But when I try to use these residues in my input sequence (ALA LEU LEU VAL BMT LMA GLY LEU VAL LEU ALA), I'm getting this error when I run simple_cycpep_predict:

ERROR: Error!  Could not open rotamer library file ncaa_rotamer_libraries/cyclosporin/BMT_Nmethylated.rotlib for read.

Post Situation: 

simple_cycpep_predict issue modifying terminal residue

Category: 
Non-Canonical Peptides

Hi, I'm trying to use simple_cycpep_predict to model the conformation of a disulfide linked cyclic peptide. The peptide has an amidated C terminus. I've been trying to get the patch Cterm_amidation working however it appears to ignore the patch.

A sample input sequence is:

CYS ALA ALA ALA ALA CYS ALA ALA ALA:Cterm_amidation

And here's my test input script:

Post Situation: 

adding greek_alphabets in non-canonical AA parameter generation

Category: 
Non-Canonical Peptides

Hello

I am running molfile_to_params_polymer.py to get the .params file for my non-canonical aa. But I got the error below. I think it might be due to the long chain of my non-canonical amino acid. I tried to increase the greek letters list in line 1655 of the script, but it did not work. Maybe it needs to modiy several lines of code.

Also, I got large numbers (as you see the error below).Can someone help to modify the code for my non-canonical  amino acid to resolve the error?

Post Situation: 

cartesian_ddg crashes when the mutfile contains multiple mutations to non-canonical residues

Category: 
Non-Canonical Peptides

Good evening,

I am experiencing an odd behaviour with the cartesian_ddg application (Rosetta version 3.11) when trying to specify multiple simultaneous mutations to non-canonical residues in the mut_file.

Post Situation: 

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