EMBOSS: extractalign

| extractalign

## Function

Extract regions from a sequence alignment

## Description

extractalign allows you to specify one or more regions of a sequence alignment to extract sub-sequences from to build up a resulting sub-sequence alignment. extractakign reads in a sequence alignment and a set of regions of that alignment as specified by pairs of start and end positions (either on the command-line or contained in a file) using gapped alignment positions as the coordinates, and writes out the specified regions of the input sequence in the order in which they have been specified. Thus, if the sequence "AAAGGGTTT" has been input and the regions: "7-9, 3-4" have been specified, then the output sequence will be: "TTTAG".

## Usage

Here is a sample session with extractalign

Extract the region from position 10 to 20:

    % extractalign dna.msf result.seq -regions '11-30'
    Extract regions from a sequence alignment

Go to the input files for this example
Go to the output files for this example

## Command line arguments

       Standard (Mandatory) qualifiers:
      [-sequence]          seqset     (Aligned) sequence set filename and optional
                                      format, or reference (input USA)
       -regions            range      [Whole sequence] Regions to extract.
                                      A set of regions is specified by a set of
                                      pairs of positions.
                                      The positions are integers.
                                      They are separated by any non-digit,
                                      non-alpha character.
                                      Examples of region specifications are:
                                      24-45, 56-78
                                      1:45, 67=99;765..888
                                      1,5,8,10,23,45,57,99
      [-outseq]            seqoutall  [.] Sequence set(s)
                                      filename and optional format (output USA)

       Additional (Optional) qualifiers: (none)
       Advanced (Unprompted) qualifiers: (none)
       Associated qualifiers:

       "-sequence" associated qualifiers
       -sbegin1            integer    Start of each sequence to be used
       -send1              integer    End of each sequence to be used
       -sreverse1          boolean    Reverse (if DNA)
       -sask1              boolean    Ask for begin/end/reverse
       -snucleotide1       boolean    Sequence is nucleotide
       -sprotein1          boolean    Sequence is protein
       -slower1            boolean    Make lower case
       -supper1            boolean    Make upper case
       -sformat1           string     Input sequence format
       -sdbname1           string     Database name
       -sid1               string     Entryname
       -ufo1               string     UFO features
       -fformat1           string     Features format
       -fopenfile1         string     Features file name

       "-outseq" associated qualifiers
       -osformat2          string     Output seq format
       -osextension2       string     File name extension
       -osname2            string     Base file name
       -osdirectory2       string     Output directory
       -osdbname2          string     Database name to add
       -ossingle2          boolean    Separate file for each entry
       -oufo2              string     UFO features
       -offormat2          string     Features format
       -ofname2            string     Features file name
       -ofdirectory2       string     Output directory

       General qualifiers:
       -auto               boolean    Turn off prompts
       -stdout             boolean    Write first file to standard output
       -filter             boolean    Read first file from standard input, write
                                      first file to standard output
       -options            boolean    Prompt for standard and additional values
       -debug              boolean    Write debug output to program.dbg
       -verbose            boolean    Report some/full command line options
       -help               boolean    Report command line options. More
                                      information on associated and general
                                      qualifiers can be found with -help -verbose
       -warning            boolean    Report warnings
       -error              boolean    Report errors
       -fatal              boolean    Report fatal errors
       -die                boolean    Report dying program messages

Standard (Mandatory) qualifiers | Allowed values | Default
--- | --- | ---
[-sequence] (Parameter 1) | (Aligned) sequence set filename and optional format, or reference (input USA) | Readable set of sequences | Required
-regions | Regions to extract. A set of regions is specified by a set of pairs of positions. The positions are integers. They are separated by any non-digit, non-alpha character. Examples of region specifications are: 24-45, 56-78 1:45, 67=99;765..888 1,5,8,10,23,45,57,99 | Sequence range | Whole sequence
[-outseq] (Parameter 2) | Sequence set(s) filename and optional format (output USA) | Writeable sequence(s) | <*>.format
Additional (Optional) qualifiers | Allowed values | Default
(none)
Advanced (Unprompted) qualifiers | Allowed values | Default
(none)

## Input file format

extractalign reads a normal sequence USA.

### Input files for usage example

### File: dna.msf

    !!NA_MULTIPLE_ALIGNMENT

     dna.msf  MSF: 120  Type: N  January 01, 1776  12:00  Check: 3196 ..

     Name: MSFM1          Len:   120  Check:  8587  Weight:  1.00
     Name: MSFM2          Len:   120  Check:  6178  Weight:  1.00
     Name: MSFM3          Len:   120  Check:  8431  Weight:  1.00

    //

            MSFM1  ACGTACGTAC GTACGTACGT ACGTACGTAC GTACGTACGT ACGTACGTAC
            MSFM2  ACGTACGTAC GTACGTACGT ....ACGTAC GTACGTACGT ACGTACGTAC
            MSFM3  ACGTACGTAC GTACGTACGT ACGTACGTAC GTACGTACGT CGTACGTACG

            MSFM1  GTACGTACGT ACGTACGTAC GTACGTACGT ACGTACGTAC GTACGTACGT
            MSFM2  GTACGTACGT ACGTACGTAC GTACGTACGT ACGTACGTAC GTACGTACGT
            MSFM3  TACGTACGTA CGTACGTACG TACGTACGTA ACGTACGTAC GTACGTACGT

            MSFM1  ACGTACGTAC GTACGTACGT
            MSFM2  ACGTACGTTG CAACGTACGT
            MSFM3  ACGTACGTAC GTACGTACGT

You can specifiy a file of ranges to extract by giving the '-regions' qualifier the value '@' followed by the name of the file containing the ranges. (eg: '-regions @myfile').

The format of the range file is:

- Comment lines start with '#' in the first column.
- Comment lines and blank lines are ignored.
- The line may start with white-space.
- There are two positive (integer) numbers per line separated by one or more space or TAB characters.
- The second number must be greater or equal to the first number.
- There can be optional text after the two numbers to annotate the line.
- White-space before or after the text is removed.

An example range file is:

    # this is my set of ranges
    12   23
     4   5       this is like 12-23, but smaller
    67   10348   interesting region

## Output file format

The output is a normal sequence file.

### Output files for usage example

### File: result.seq

    >MSFM1
    GTACGTACGTACGTACGTAC
    >MSFM2
    GTACGTACGT----ACGTAC
    >MSFM3
    GTACGTACGTACGTACGTAC

If the option '-separate' is used then each specified region is written to the output file as a separate sequence. The name of the sequence is created from the name of the original sequence with the start and end positions of the range appended with underscore characters between them,

For example: "XYZ region 2 to 34" is written as: "XYZ_2_34"

## Data files

None.

## Notes

None.

## References

None.

## Warnings

None.

## Diagnostic Error Messages

Several warning messages about malformed region specifications:

- Non-digit found in region ...
- Unpaired start of a region found in ...
- Non-digit found in region ...
- The start of a pair of region positions must be smaller than the end in ...

## Exit status

It exits with status 0, unless a region is badly constructed.

## Known bugs

None noted.

## Comments

## See also

Program name | Description
--- | ---
aligncopy | Reads and writes alignments
aligncopypair | Reads and writes pairs from alignments
biosed | Replace or delete sequence sections
codcopy | Copy and reformat a codon usage table
cutseq | Removes a section from a sequence
degapseq | Removes non-alphabetic (e.g. gap) characters from sequences
descseq | Alter the name or description of a sequence
entret | Retrieves sequence entries from flatfile databases and files
extractfeat | Extract features from sequence(s)
extractseq | Extract regions from a sequence
featcopy | Reads and writes a feature table
featreport | Reads and writes a feature table
listor | Write a list file of the logical OR of two sets of sequences
makenucseq | Create random nucleotide sequences
makeprotseq | Create random protein sequences
maskambignuc | Masks all ambiguity characters in nucleotide sequences with N
maskambigprot | Masks all ambiguity characters in protein sequences with X
maskfeat | Write a sequence with masked features
maskseq | Write a sequence with masked regions
newseq | Create a sequence file from a typed-in sequence
nohtml | Remove mark-up (e.g. HTML tags) from an ASCII text file
noreturn | Remove carriage return from ASCII files
nospace | Remove all whitespace from an ASCII text file
notab | Replace tabs with spaces in an ASCII text file
notseq | Write to file a subset of an input stream of sequences
nthseq | Write to file a single sequence from an input stream of sequences
pasteseq | Insert one sequence into another
revseq | Reverse and complement a nucleotide sequence
seqret | Reads and writes (returns) sequences
seqretsplit | Reads sequences and writes them to individual files
sizeseq | Sort sequences by size
skipredundant | Remove redundant sequences from an input set
skipseq | Reads and writes (returns) sequences, skipping first few
splitter | Split sequence(s) into smaller sequences
trimest | Remove poly-A tails from nucleotide sequences
trimseq | Remove unwanted characters from start and end of sequence(s)
trimspace | Remove extra whitespace from an ASCII text file
union | Concatenate multiple sequences into a single sequence
vectorstrip | Removes vectors from the ends of nucleotide sequence(s)
yank | Add a sequence reference (a full USA) to a list file

## Author(s)

Peter Rice (pmr © ebi.ac.uk)
Informatics Division, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK

## History

## Target users

This program is intended to be used by everyone and everything, from naive users to embedded scripts.

## Comments

None