/// <summary>
/// Performs an in silico digestion of all the proteins found within the fasta file.
/// </summary>
/// <param name="fastaFile">The fasta filename to perfrom the digestion on</param>
/// <param name="uniquePeptides">The unique peptides that were read in from the csv files</param>
/// <param name="proteases"></param>
/// <param name="semiDigestion">Perform a Semi Digestion</param>
/// <returns>True if all the unique peptides get isMapped to at least one protein, false otherwise</returns>
private List<Protein> GetMappedProteinsFromFasta(string fastaFile, Dictionary<string, Peptide> uniquePeptides, IList<Protease> proteases, bool semiDigestion = false)
{
string fastaFileniceName = Path.GetFileName(fastaFile);
StringBuilder sb = new StringBuilder();
foreach (Protease protease in proteases)
{
sb.Append(protease.Name);
sb.Append(',');
}
if (sb.Length > 0) { sb.Remove(sb.Length - 1, 1); }
Log("Performing {0}{1} digestion on {2}...", semiDigestion ? "semi " : "", sb, fastaFileniceName);
//Peptide.MappedCount = 0;
int forwardProteins = 0, decoyProteins = 0, forwardProteinsMapped = 0, decoyProteinsMapped = 0, fastaCounter = 0, pepsMapped = 0;
long totalBytes = new FileInfo(fastaFile).Length;
// A hashset of all proteins that have a peptide that was in the input files
Dictionary<Protein, Protein> proteins = new Dictionary<Protein, Protein>(1 << 13);
// Min and Max length of peptides
int minLength = semiDigestion ? 1 : _smallestPeptide - 1;
int maxLength = semiDigestion ? int.MaxValue : _largestPeptide + 1;
// Open the reader for the protein database in the .fasta format
using (FastaReader reader = new FastaReader(fastaFile))
{
// Read in each protein one-by-one
foreach (Fasta fasta in reader.ReadNextFasta())
{
// The number of fasta (proteins) read in (for progress bar feedback)
fastaCounter++;
// Create a new protein from the fasta
Protein prot = new Protein(fasta.Description, fasta.Sequence);
// Check if the protein is a decoy protein or not
if (prot.IsDecoy)
{
decoyProteins++;
}
else
{
forwardProteins++;
}
// Loop over each protease
foreach (Protease protease in proteases)
{
// Digest the protein's leucine sequences (all I's are now L's) with the given proteases, max missed cleavages, limiting it to the smallest and largest peptide observed (speed improvement)
// *Note each peptide sequence (pep_seq) will be leucine sequences as well
foreach (string pepSeq in AminoAcidPolymer.Digest(prot.Sequence, protease, MaxMissedCleavages, minLength, maxLength, semiDigestion: semiDigestion))
{
// Is this one of the unique peptide sequences in the csv files? If not, we don't care about it
Peptide pep;
if (!uniquePeptides.TryGetValue(pepSeq.Replace('I', 'L'), out pep))
continue;
// Check to see if this protein has already been added to the list of proteins hit
if(!proteins.ContainsKey(prot)) // returns true if the protein is new to the hashset of proteins
{
proteins.Add(prot, prot);
if (prot.IsDecoy)
{
decoyProteinsMapped++;
}
else
{
forwardProteinsMapped++;
}
}
// Add the peptide to the protein (internally hashed, so don't worry about duplicates)
prot.AddPeptide(pep);
// Mark that this peptide was successfully mapped, this is for error checking purposes
if (!pep.IsMapped)
{
pepsMapped++;
pep.IsMapped = true;
}
//pep.MarkAsMapped();
}
}
// Only call every 100 proteins otherwise you are wasting a lot of time refreshing and not doing actual work
//if (fastaCounter > 100)
//{
// fastaCounter = 0;
// ProgressUpdate((double)reader.Position / totalBytes);
//}
}
}
// Check to see if every peptide is matched, if not try using a brute force search method instead
if (uniquePeptides.Count > pepsMapped)
{
// Get all the peptides that weren't mapped
List<Peptide> unMapedPeptides = uniquePeptides.Values.Where(p => !p.IsMapped).ToList();
Log("[WARNING] Couldn't find every peptide using digestion method (wrong enzyme perhaps?), trying brute force search instead on the remaining {0} peptides...", unMapedPeptides.Count);
ProgressUpdate(0.1);
using (FastaReader reader = new FastaReader(fastaFile))
{
fastaCounter = 0;
// Read in each protein one-by-one
foreach (Fasta fasta in reader.ReadNextFasta())
{
string seq = fasta.Sequence.Replace('I', 'L');
foreach (Peptide pep2 in unMapedPeptides)
{
if (!seq.Contains(pep2.LeucineSequence))
continue;
Protein prot = new Protein(fasta.Description, fasta.Sequence);
Protein realProt;
if (proteins.TryGetValue(prot, out realProt))
{
// Add the peptide to the protein
realProt.AddPeptide(pep2);
}
else
{
proteins.Add(prot, prot);
if (prot.IsDecoy)
{
decoyProteinsMapped++;
}
else
{
forwardProteinsMapped++;
}
// Add the peptide to the protein
prot.AddPeptide(pep2);
}
// Mark that this peptide was successfully isMapped, this is for error checking purposes
pep2.IsMapped = true;
//pep2.MarkAsMapped();
}
fastaCounter++;
//// Only call every 100 proteins otherwise you are wasting a lot of time refreshing and not doing actual work
//if (fastaCounter > 100)
//{
// fastaCounter = 0;
// ProgressUpdate((double)reader.BaseStream.Position / totalBytes);
//}
}
}
// Still missing peptides?
if (unMapedPeptides.Any(p => !p.IsMapped))
{
int count = 0;
foreach (Peptide pep2 in unMapedPeptides)
{
if (pep2.IsMapped)
continue;
count++;
Log("[ERROR]\tPeptide {0} was not isMapped", pep2);
}
throw new ArgumentException(
string.Format(
"[ERROR] Unable to map every peptide ({0}) to {1}. You might be using either the wrong database, enzyme, or max missed cleavages!",
count, fastaFileniceName));
}
}
Log("Every unique peptide was successfully mapped to at least one protein");
Log("{0:N0} of {1:N0} ({2:F2}%) target proteins were mapped at least once", forwardProteinsMapped, forwardProteins, 100.0 * (double)forwardProteinsMapped / (double)forwardProteins);
Log("{0:N0} of {1:N0} ({2:F2}%) decoy proteins were mapped at least once", decoyProteinsMapped, decoyProteins, 100.0 * (double)decoyProteinsMapped / (double)decoyProteins);
// force the progress bar to go into marquee mode
ProgressUpdate(0.0);
// Return a list of all the proteins that were isMapped at least once
return proteins.Values.ToList();
}
public void WriteFasta(string fasta_file, FastaWriter Writer)
{
bool MakeDecoy = false;
if (Options.OutputType == DatabaseType.Target || Options.OutputType == DatabaseType.Concatenated)
{
MakeDecoy = false;
}
else if (Options.OutputType == DatabaseType.Decoy || Options.OutputType == DatabaseType.Concatenated)
{
MakeDecoy = true;
}
using (FastaReader reader = new FastaReader(fasta_file))
{
foreach (Fasta fasta in reader.ReadNextFasta())
{
Regex uniprotRegex = new Regex(@"(.+)\|(.+)\|(.+?)\s(.+?)\sOS=(.+?)(?:\sGN=(.+?))?(?:$|PE=(\d+)\sSV=(\d+))", RegexOptions.ExplicitCapture);
Match UniprotMatch = uniprotRegex.Match(fasta.Description);
string HeaderFile = "InvalidUniprotheaders.txt";
string headerFolder = Path.GetDirectoryName(Options.InputFiles[0]);
if (Options.EnforceUniprot && !UniprotMatch.Success)
{
using (StreamWriter log = new StreamWriter(Path.Combine(headerFolder, HeaderFile), true))
{
log.WriteLine("Invalid Header:");
log.WriteLine();
log.WriteLine(fasta.Description);
log.WriteLine();
InvalidHeader(fasta);
}
}
if (UniprotMatch.Success)
{
bool excludeMethionine = false;
if (Options.ExcludeNTerminalMethionine && !Options.ExcludeNTerminalResidue)
{
excludeMethionine = true;
}
if (MakeDecoy)
{
Writer.Write(fasta.ToDecoy(Options.DecoyPrefix, Options.DecoyType, (excludeMethionine || Options.ExcludeNTerminalResidue), Options.ExcludeNTerminalMethionine));
}
else
{
Writer.Write(fasta);
}
}
}
}
}