Hello everyone, I'd like to pile on with a few OMSSA questions.
I'd like to include OMSSA, probID and Tandem in an automated search
scheme for the same data and this is proving problematic when managing
the OMSSA output.
First a quick overview...

I run an OMSSA search from the command line on an MGF file converted
from an mzXML using the -op and an e-value cutoff of 1e6 to get a
pep.xml output with plenty of decoy hits from the database.
When the search is complete I edit the resulting pep.xml file
summary_base_name and search_base_name lines to point at the mzXML
file rather than the output pep.xml.
I then run interactparser with the-P option to fix the protein names,
and refreshparser to point to the correct database.

>From here I can succesfully take the file through each of the parser
steps like found in some of the other threads in this group:
i.e.
interactparser out.pep.xml-L5 - Etrypsin -C -P fix.pep.xml
refreshparser fix.pep.xml c:\blastdb\omssaTMP.fasta
peptideprophetparser fix.pep.xml DECOY=decoy_ MINPROB=0 NONPARAM
proteinprophet fix.pep.xml fix.prot.xml NOOCCAM NOGROUPS

However trying to read the file with pep.xml viewer just gives me the
error message:
unable to read pepxml file: error parsing pepxml file: XML parsing
error: not well-formed (invalid token), at xml file line 11, column 62

The Prot.xml is viewable.

Running all steps  through Xinteract also crashes at pepxmlviewer
step.
Has anyone been able to take their OMSSA results through the TPP in
such a way that the final pep.xml is viewable with pepxmlviewer?
If you have an example of a working pep.xml file or a quick workflow
to share that would be excellent.

On a side note all analysis of OMSSA pep.xml I have seen use MINPROB=0
for the peptideprophetparser step, is there a reason for this?
Why don't I want to exclude lower probability peptides in OMSSAs case,
and is Occams razor and protein grouping not applicable in OMSSAs
case?
Since I'd like to combine the OMSSA output with other output this is
something that I'd like to understand before proceeding.

If anyone has the time and energy to give me any input on this it
would be much appreciated.

/Erik

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