findORFs {ORFik} | R Documentation

## Find Open Reading Frames.

### Description

Find all Open Reading Frames (ORFs) on the simple input sequences in ONLY 5'- 3' direction (+), but within all three possible reading frames. Do not use findORFs for mapping to full chromosomes, then use `findMapORFs`! For each sequence of the input vector `IRanges` with START and STOP positions (inclusive) will be returned as `IRangesList`. Returned coordinates are relative to the input sequences.

### Usage

    findORFs(
      seqs,
      startCodon = startDefinition(1),
      stopCodon = stopDefinition(1),
      longestORF = TRUE,
      minimumLength = 0
    )

### Arguments

`seqs` | (DNAStringSet or character vector) - DNA/RNA sequences to search for Open Reading Frames. Can be both uppercase or lowercase. Easiest call to get seqs if you want only regions from a fasta/fasta index pair is: seqs = ORFik:::txSeqsFromFa(grl, faFile), where grl is a GRanges/List of search regions and faFile is a `FaFile`.
`startCodon` | (character vector) Possible START codons to search for. Check `startDefinition` for helper function.
`stopCodon` | (character vector) Possible STOP codons to search for. Check `stopDefinition` for helper function.
`longestORF` | (logical) Default TRUE. Keep only the longest ORF per unique stopcodon: (seqname, strand, stopcodon) combination, Note: Not longest per transcript! You can also use function `longestORFs` after creation of ORFs for same result.
`minimumLength` | (integer) Default is 0. Which is START + STOP = 6 bp. Minimum length of ORF, without counting 3bps for START and STOP codons. For example minimumLength = 8 will result in size of ORFs to be at least START + 8*3 (bp) + STOP = 30 bases. Use this param to restrict search.

### Details

If you want antisence strand too, do: `#positive strands pos <- findORFs(seqs) #negative strands (DNAStringSet only if character) neg <- findORFs(reverseComplement(DNAStringSet(seqs))) relist(c(GRanges(pos, strand = "+"), GRanges(neg, strand = "-")), skeleton = merge(pos, neg))`

### Value

(IRangesList) of ORFs locations by START and STOP sites grouped by input sequences. In a list of sequences, only the indices of the sequences that had ORFs will be returned, e.g. 3 sequences where only 1 and 3 has ORFs, will return size 2 IRangesList with names c("1", "3"). If there are a total of 0 ORFs, an empty IRangesList will be returned.

### See Also

Other findORFs: `findMapORFs()`, `findORFsFasta()`, `findUORFs()`, `startDefinition()`, `stopDefinition()`

### Examples

    ## Simple examples
    findORFs("ATGTAA")
    findORFs("ATGTTAA") # not in frame anymore

    findORFs("ATGATGTAA") # only longest of two above
    findORFs("ATGATGTAA", longestORF = FALSE) # two ORFs

    findORFs(c("ATGTAA", "ATGATGTAA")) # 1 ORF per transcript

    ## Get DNA sequences from ORFs
    seq <- DNAStringSet(c("ATGTAA", "AAA", "ATGATGTAA"))
    names(seq) <- c("tx1", "tx2", "tx3")
    orfs <- findORFs(seq, longestORF = FALSE)

    #  you can get sequences like this:
    gr <- unlist(orfs, use.names = TRUE)
    gr <- GRanges(seqnames = names(seq)[as.integer(names(gr))],
     ranges(gr), strand = "+")
    # Give them some proper names:
    names(gr) <- paste0("ORF_", seq.int(length(gr)), "_", seqnames(gr))
    orf_seqs <- getSeq(seq, gr)
    orf_seqs
    # Save as .fasta (orf_seqs must be of type DNAStringSet)
    # writeXStringSet(orf_seqs, "orfs.fasta")
    ## Reading from file and find ORFs
    #findORFs(readDNAStringSet("path/to/transcripts.fasta"))

[Package ORFik version 1.14.7 Index]