profisis(1) protein-protein interaction sites identified from sequence


profisis [OPTION]


profisis (ISIS) is a machine learning-based method that identifies interacting residues from sequence alone. Although the method is developed using transient protein-protein interfaces from complexes of experimentally known 3D structures, it never explicitly uses 3D infor- mation. Instead, we combine predicted structural features with evolutionary information. The strongest predictions of the method reached over 90% accuracy in a cross-validation experiment. Our results suggest that despite the significant diversity in the nature of protein-protein interactions, they all share common basic principles and that these principles are identifiable from sequence alone.

Conversion of PSI-BLAST alignment to HSSP format

The most up-to-date procedure can be found at <>.
1. Convert BLAST output to a Single Alignment Format (SAF):
 /usr/share/librg-utils-perl/ fasta=<query_fasta_file> maxAli=3000 eSaf=1 \
  saf=<saf_formatted_file> <blast_output>
2. Convert SAF format to HSSP:
 /usr/share/librg-utils-perl/ <saf_formatted_file> formatIn=saf formatOut=hssp \
  fileOut=<hssp_formatted_file> exeConvertSeq=convert_seq
3. Filter results to 80% redundancy:
 /usr/share/librg-utils-perl/ red=80 <hssp_formatted_file> fileOut=<filtered_hssp_formatted_file>

Output format

See description of --outformat option.


Ofran, Y. and Rost, B. (2007). ISIS: interaction sites identified from sequence. Bioinformatics, 23(2), e13-6.


Required parameters
file that contains your sequence in fasta format
file with hssp data for sequence in --fastafile
file with prof output for sequence in --fastafile
output file

Optional parameters

output format [pp|prval], default=pp
PredictProtein format:

 Output ::= Header_Line Binary_Out Raw_Out
 Header_Line ::= '>' Header_String '\n'
 Binary_Out ::= ( Horiz_Sequence '\n' Bin_Pred '\n\n' )+
 Horiz_Sequence ::= Amino_Acid_One_Letter_Code{,40}
 Bin_Pred ::= [P-]{,40}

'P' marks binding residue.

 Raw_Out ::= ( Amino_Acid_Number ' ' Amino_Acid_One_Letter_Code ' ' Prediction_Score '\n' )+
 Prediction_Score ::= Integer_Value

See example outputs in /usr/share/doc/profisis/examples.

( 'resn resi predicted_value' )+, e.g.

 '1 M 25'
 '2 R 36'
Default: --nodebug
Succinct output (print no confidence values).

Parameters controlling post processing - these parameters affect only the top part of the 'pp' output format

Default: --crd-restriction. Use original ($crd = undef) code (--crd-restriction) or use new ($cr) code (--nocrd-restriction).


 profisis --fastafile /usr/share/doc/profisis/examples/3A1P_A.fasta --hsspfile /usr/share/doc/profisis/examples/3A1P_A.hssp --rdbproffile /usr/share/doc/profisis/examples/3A1P_A.rdbProf --outfile /tmp/3A1P_A.profisis


Location of configuration file to use, overriding other configuration files


Default configuration file. See this file for a description of the parameters.
System configuration file overriding values in /usr/share/profisis/profisisrc.default
User configuration file overriding values in /etc/profisisrc
If this environment variable is set ~/.profisisrc is disregarded and the value of the variable is read for configuration options overriding /etc/profisisrc


Yanay Ofran and Burkhard Rost