#!/usr/bin/python """ Returns a bed-like translation of a CDS in which each record corresponds to a single site in the CDS and includes additional fields for site degenaracy, position ind CDS, and amino acid encoded. usage: %prog nibdir genefile [options] -o, --outfile=o: output file -f, --format=f: format bed (default), or gtf|gff -a, --allpositions: 1st, 2nd and 3rd positions are evaluated for degeneracy given the sequence at the other two positions. Many 1d sites in 1st codon positions become 2d sites when considered this way. -n, --include_name: include the 'name' or 'id' field from the source file on every line of output """ import os import re import sys from bx.cookbook import doc_optparse from bx.gene_reader import CDSReader from bx.seq import nib GENETIC_CODE = """ TTT (Phe/F)Phenylalanine TTC (Phe/F)Phenylalanine TTA (Leu/L)Leucine TTG (Leu/L)Leucine, Start TCT (Ser/S)Serine TCC (Ser/S)Serine TCA (Ser/S)Serine TCG (Ser/S)Serine TAT (Tyr/Y)Tyrosine TAC (Tyr/Y)Tyrosine TAA Ochre (Stop) TAG Amber (Stop) TGT (Cys/C)Cysteine TGC (Cys/C)Cysteine TGA Opal (Stop) TGG (Trp/W)Tryptophan CTT (Leu/L)Leucine CTC (Leu/L)Leucine CTA (Leu/L)Leucine CTG (Leu/L)Leucine, Start CCT (Pro/P)Proline CCC (Pro/P)Proline CCA (Pro/P)Proline CCG (Pro/P)Proline CAT (His/H)Histidine CAC (His/H)Histidine CAA (Gln/Q)Glutamine CAG (Gln/Q)Glutamine CGT (Arg/R)Arginine CGC (Arg/R)Arginine CGA (Arg/R)Arginine CGG (Arg/R)Arginine ATT (Ile/I)Isoleucine, Start2 ATC (Ile/I)Isoleucine ATA (Ile/I)Isoleucine ATG (Met/M)Methionine, Start1 ACT (Thr/T)Threonine ACC (Thr/T)Threonine ACA (Thr/T)Threonine ACG (Thr/T)Threonine AAT (Asn/N)Asparagine AAC (Asn/N)Asparagine AAA (Lys/K)Lysine AAG (Lys/K)Lysine AGT (Ser/S)Serine AGC (Ser/S)Serine AGA (Arg/R)Arginine AGG (Arg/R)Arginine GTT (Val/V)Valine GTC (Val/V)Valine GTA (Val/V)Valine GTG (Val/V)Valine, Start2 GCT (Ala/A)Alanine GCC (Ala/A)Alanine GCA (Ala/A)Alanine GCG (Ala/A)Alanine GAT (Asp/D)Aspartic acid GAC (Asp/D)Aspartic acid GAA (Glu/E)Glutamic acid GAG (Glu/E)Glutamic acid GGT (Gly/G)Glycine GGC (Gly/G)Glycine GGA (Gly/G)Glycine GGG (Gly/G)Glycine """ def translate(codon, genetic_code): c1, c2, c3 = codon return genetic_code[c1][c2][c3] """ parse the doc string to hash the genetic code""" GEN_CODE = {} for line in GENETIC_CODE.split("\n"): if line.strip() == "": continue f = re.split(r"\s|\(|\)|\/", line) codon = f[0] c1, c2, c3 = codon aminoacid = f[3] if c1 not in GEN_CODE: GEN_CODE[c1] = {} if c2 not in GEN_CODE[c1]: GEN_CODE[c1][c2] = {} GEN_CODE[c1][c2][c3] = aminoacid def getnib(nibdir): seqs = {} for nibf in os.listdir(nibdir): if not nibf.endswith(".nib"): continue chr = nibf.replace(".nib", "") file = os.path.join(nibdir, nibf) seqs[chr] = nib.NibFile(open(file)) return seqs REVMAP = str.maketrans("ACGTacgt", "TGCAtgca") def revComp(seq): return seq[::-1].translate(REVMAP) def Comp(seq): return seq.translate(REVMAP) def main(): options, args = doc_optparse.parse(__doc__) try: if options.outfile: out = open(options.outfile, "w") else: out = sys.stdout if options.format: format = options.format else: format = "bed" allpositions = bool(options.allpositions) include_name = bool(options.include_name) nibdir = args[0] bedfile = args[1] except Exception: doc_optparse.exit() nibs = getnib(nibdir) for chrom, strand, cds_exons, name in CDSReader(open(bedfile), format=format): cds_seq = "" # genome_seq_index maps the position in CDS to position on the genome genome_seq_index = [] for c_start, c_end in cds_exons: cds_seq += nibs[chrom].get(c_start, c_end - c_start) for i in range(c_start, c_end): genome_seq_index.append(i) cds_seq = cds_seq.upper() if strand == "+": frsts = range(0, len(cds_seq), 3) offsign = 1 else: cds_seq = Comp(cds_seq) frsts = range(2, len(cds_seq), 3) offsign = -1 offone = 1 * offsign offtwo = 2 * offsign all = ["A", "C", "G", "T"] for first_pos in frsts: c1 = first_pos c2 = first_pos + offone c3 = first_pos + offtwo try: assert c3 < len(cds_seq) except AssertionError: print("out of sequence at %d for %s, %d" % (c3, chrom, genome_seq_index[first_pos]), file=sys.stderr) continue codon = cds_seq[c1], cds_seq[c2], cds_seq[c3] aa = translate(codon, GEN_CODE) degeneracy3 = str(list(GEN_CODE[codon[0]][codon[1]].values()).count(aa)) + "d" if not include_name: name_text = "" else: name_text = name.replace(" ", "_") if allpositions: try: degeneracy1 = str([GEN_CODE[k][codon[1]][codon[2]] for k in all].count(aa)) + "d" degeneracy2 = str([GEN_CODE[codon[0]][k][codon[2]] for k in all].count(aa)) + "d" except TypeError as s: print(list(GEN_CODE.values()), file=sys.stderr) raise TypeError(s) if strand == "+": print( chrom, genome_seq_index[c1], genome_seq_index[c1] + 1, cds_seq[c1], degeneracy1, aa, name_text, file=out, ) print( chrom, genome_seq_index[c2], genome_seq_index[c2] + 1, cds_seq[c2], degeneracy2, aa, name_text, file=out, ) print( chrom, genome_seq_index[c3], genome_seq_index[c3] + 1, cds_seq[c3], degeneracy3, aa, name_text, file=out, ) else: print( chrom, genome_seq_index[c3], genome_seq_index[c3] + 1, cds_seq[c3], degeneracy3, aa, name_text, file=out, ) print( chrom, genome_seq_index[c2], genome_seq_index[c2] + 1, cds_seq[c2], degeneracy2, aa, name_text, file=out, ) print( chrom, genome_seq_index[c1], genome_seq_index[c1] + 1, cds_seq[c1], degeneracy1, aa, name_text, file=out, ) else: if strand == "+": for b in c1, c2: print( chrom, genome_seq_index[b], genome_seq_index[b] + 1, cds_seq[b], "1d", aa, name_text, file=out, ) print( chrom, genome_seq_index[c3], genome_seq_index[c3] + 1, cds_seq[c3], degeneracy3, aa, name_text, file=out, ) else: print( chrom, genome_seq_index[c3], genome_seq_index[c3] + 1, cds_seq[c3], degeneracy3, aa, name_text, file=out, ) for b in c2, c1: print( chrom, genome_seq_index[b], genome_seq_index[b] + 1, cds_seq[b], "1d", aa, name_text, file=out, ) out.close() if __name__ == "__main__": main()