dreg

 

Function

regular expression search of a nucleotide sequence

Description

This searches for matches of a regular expression to a nucleic acid sequence.

A regular expression is a way of specifying an ambiguous pattern to search for. Regular expressions are commonly used in some computer programming languages and may be more familiar to some users than to others.

The following is a short guide to regular expressions in EMBOSS:

^
use this at the start of a pattern to insist that the pattern can only match at the start of a sequence. (eg. '^AUG' matches a start codon at the start of the sequence)
$
use this at the end of a pattern to insist that the pattern can only match at the end of a sequence (eg. 'A+$' matches a poly-A sequence at the end of the sequence)
()
groups a pattern. This is commonly used with '|' (eg. '(AUG)|(ATG)' matches either the DNA or RNA form of the initiation codon )
|
This is the OR operator to enable a match to be made to either one pattern OR another. There is no AND operator in this version of regular expressions.

The following quantifier characters specify the number of time that the character before (in this case 'x') matches:

x?
matches 0 or 1 times (ie, '' or 'x')
x*
matches 0 or more times (ie, '' or 'x' or 'xx' or 'xxx', etc)
x+
matches 1 or more times (ie, 'x' or 'xx' or 'xxx', etc)

Quantifiers can follow any of the following types of character specification:

x
any character (ie 'A')
\x
the character after the backslash is used instead of its normal regular expression meaning. This is commonly used to turn off the special meaning of the characters '^$()|?*+[]-.'. It may be especially useful when searching for gap characters in a sequence (eg '\.' matches only a dot character '.')
[xy]
match one of the characters 'x' or 'y'. You may have one or more characters in this set.
[x-z]
match any one of the set of characters starting with 'x' and ending in 'y' in ASCII order (eg '[A-G]' matches any one of: 'A', 'B', 'C', 'D', 'E', 'F', 'G')
[^x-z]
matches anything except any one of the group of characters in ASCII order (eg '[^A-G]' matches anything EXCEPT any one of: 'A', 'B', 'C', 'D', 'E', 'F', 'G')
.
the dot character matches any other character (eg: 'A.G' matches 'AAG', 'AaG', 'AZG', 'A-G' 'A G', etc.)
Combining some of these features gives the example:
'([AGC]+GGG)|(TTTGGG)'
which matches one or more of any one of 'A' or 'G' or 'C' followed by three 'G's or it matches just 'TTTGGG'.

Regular expressions are case-sensitive. The pattern 'AAAA' will not match the sequence 'aaaa'.

Usage

Here is a sample session with dreg


% dreg 
regular expression search of a nucleotide sequence
Input sequence(s): tembl:paamir
Regular expression pattern: ggtacc
Output file [paamir.dreg]: 

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

Command line arguments

   Mandatory qualifiers:
  [-sequence]          seqall     Sequence database USA
  [-pattern]           regexp     Regular expression pattern
  [-outfile]           outfile    Output file name

   Optional qualifiers: (none)
   Advanced qualifiers: (none)
   General qualifiers:
  -help                boolean    Report command line options. More
                                  information on associated and general
                                  qualifiers can be found with -help -verbose


Mandatory qualifiers Allowed values Default
[-sequence]
(Parameter 1)
Sequence database USA Readable sequence(s) Required
[-pattern]
(Parameter 2)
Regular expression pattern Any regular epression pattern is accepted Required
[-outfile]
(Parameter 3)
Output file name Output file <sequence>.dreg
Optional qualifiers Allowed values Default
(none)
Advanced qualifiers Allowed values Default
(none)

Input file format

Any nucleic sequence.

Input files for usage example

'tembl:paamir' is a sequence entry in the example nucleic acid database 'tembl'

Database entry: tembl:paamir

ID   PAAMIR     standard; DNA; PRO; 2167 BP.
XX
AC   X13776; M43175;
XX
SV   X13776.1
XX
DT   19-APR-1989 (Rel. 19, Created)
DT   17-FEB-1997 (Rel. 50, Last updated, Version 22)
XX
DE   Pseudomonas aeruginosa amiC and amiR gene for aliphatic amidase regulation
XX
KW   aliphatic amidase regulator; amiC gene; amiR gene.
XX
OS   Pseudomonas aeruginosa
OC   Bacteria; Proteobacteria; gamma subdivision; Pseudomonadaceae; Pseudomonas.
XX
RN   [1]
RP   1167-2167
RA   Rice P.M.;
RT   ;
RL   Submitted (16-DEC-1988) to the EMBL/GenBank/DDBJ databases.
RL   Rice P.M., EMBL, Postfach 10-2209, Meyerhofstrasse 1, 6900 Heidelberg, FRG.
XX
RN   [2]
RP   1167-2167
RX   MEDLINE; 89211409.
RA   Lowe N., Rice P.M., Drew R.E.;
RT   "Nucleotide sequence of the aliphatic amidase regulator gene of Pseudomonas
RT   aeruginosa";
RL   FEBS Lett. 246:39-43(1989).
XX
RN   [3]
RP   1-1292
RX   MEDLINE; 91317707.
RA   Wilson S., Drew R.;
RT   "Cloning and DNA seqence of amiC, a new gene regulating expression of the
RT   Pseudomonas aeruginosa aliphatic amidase, and purification of the amiC
RT   product.";
RL   J. Bacteriol. 173:4914-4921(1991).
XX
RN   [4]
RP   1-2167
RA   Rice P.M.;
RT   ;
RL   Submitted (04-SEP-1991) to the EMBL/GenBank/DDBJ databases.
RL   Rice P.M., EMBL, Postfach 10-2209, Meyerhofstrasse 1, 6900 Heidelberg, FRG.
XX
DR   SWISS-PROT; P10932; AMIR_PSEAE.
DR   SWISS-PROT; P27017; AMIC_PSEAE.
DR   SWISS-PROT; Q51417; AMIS_PSEAE.


  [Part of this file has been deleted for brevity]

FT                   phenotype"
FT                   /replace=""
FT                   /gene="amiC"
FT   misc_feature    1
FT                   /note="last base of an XhoI site"
FT   misc_feature    648..653
FT                   /note="end of 658bp XhoI fragment, deletion in  pSW3 causes
FT                   constitutive expression of amiE"
FT   conflict        1281
FT                   /replace="g"
FT                   /citation=[3]
XX
SQ   Sequence 2167 BP; 363 A; 712 C; 730 G; 362 T; 0 other;
     ggtaccgctg gccgagcatc tgctcgatca ccaccagccg ggcgacggga actgcacgat        60
     ctacctggcg agcctggagc acgagcgggt tcgcttcgta cggcgctgag cgacagtcac       120
     aggagaggaa acggatggga tcgcaccagg agcggccgct gatcggcctg ctgttctccg       180
     aaaccggcgt caccgccgat atcgagcgct cgcacgcgta tggcgcattg ctcgcggtcg       240
     agcaactgaa ccgcgagggc ggcgtcggcg gtcgcccgat cgaaacgctg tcccaggacc       300
     ccggcggcga cccggaccgc tatcggctgt gcgccgagga cttcattcgc aaccgggggg       360
     tacggttcct cgtgggctgc tacatgtcgc acacgcgcaa ggcggtgatg ccggtggtcg       420
     agcgcgccga cgcgctgctc tgctacccga ccccctacga gggcttcgag tattcgccga       480
     acatcgtcta cggcggtccg gcgccgaacc agaacagtgc gccgctggcg gcgtacctga       540
     ttcgccacta cggcgagcgg gtggtgttca tcggctcgga ctacatctat ccgcgggaaa       600
     gcaaccatgt gatgcgccac ctgtatcgcc agcacggcgg cacggtgctc gaggaaatct       660
     acattccgct gtatccctcc gacgacgact tgcagcgcgc cgtcgagcgc atctaccagg       720
     cgcgcgccga cgtggtcttc tccaccgtgg tgggcaccgg caccgccgag ctgtatcgcg       780
     ccatcgcccg tcgctacggc gacggcaggc ggccgccgat cgccagcctg accaccagcg       840
     aggcggaggt ggcgaagatg gagagtgacg tggcagaggg gcaggtggtg gtcgcgcctt       900
     acttctccag catcgatacg cccgccagcc gggccttcgt ccaggcctgc catggtttct       960
     tcccggagaa cgcgaccatc accgcctggg ccgaggcggc ctactggcag accttgttgc      1020
     tcggccgcgc cgcgcaggcc gcaggcaact ggcgggtgga agacgtgcag cggcacctgt      1080
     acgacatcga catcgacgcg ccacaggggc cggtccgggt ggagcgccag aacaaccaca      1140
     gccgcctgtc ttcgcgcatc gcggaaatcg atgcgcgcgg cgtgttccag gtccgctggc      1200
     agtcgcccga accgattcgc cccgaccctt atgtcgtcgt gcataacctc gacgactggt      1260
     ccgccagcat gggcggggga ccgctcccat gagcgccaac tcgctgctcg gcagcctgcg      1320
     cgagttgcag gtgctggtcc tcaacccgcc gggggaggtc agcgacgccc tggtcttgca      1380
     gctgatccgc atcggttgtt cggtgcgcca gtgctggccg ccgccggaag ccttcgacgt      1440
     gccggtggac gtggtcttca ccagcatttt ccagaatggc caccacgacg agatcgctgc      1500
     gctgctcgcc gccgggactc cgcgcactac cctggtggcg ctggtggagt acgaaagccc      1560
     cgcggtgctc tcgcagatca tcgagctgga gtgccacggc gtgatcaccc agccgctcga      1620
     tgcccaccgg gtgctgcctg tgctggtatc ggcgcggcgc atcagcgagg aaatggcgaa      1680
     gctgaagcag aagaccgagc agctccagga ccgcatcgcc ggccaggccc ggatcaacca      1740
     ggccaaggtg ttgctgatgc agcgccatgg ctgggacgag cgcgaggcgc accagcacct      1800
     gtcgcgggaa gcgatgaagc ggcgcgagcc gatcctgaag atcgctcagg agttgctggg      1860
     aaacgagccg tccgcctgag cgatccgggc cgaccagaac aataacaaga ggggtatcgt      1920
     catcatgctg ggactggttc tgctgtacgt tggcgcggtg ctgtttctca atgccgtctg      1980
     gttgctgggc aagatcagcg gtcgggaggt ggcggtgatc aacttcctgg tcggcgtgct      2040
     gagcgcctgc gtcgcgttct acctgatctt ttccgcagca gccgggcagg gctcgctgaa      2100
     ggccggagcg ctgaccctgc tattcgcttt tacctatctg tgggtggccg ccaaccagtt      2160
     cctcgag                                                                2167
//

Output file format

Output files for usage example

File: paamir.dreg

dreg search of tembl:paamir with pattern GGTACC
Matches in PAAMIR
         PAAMIR     1 GGTACC

Data files

None.

Notes

None.

References

None.

Warnings

Regular expressions are case-sensitive. The pattern 'AAAA' will not match the sequence 'aaaa'.

Diagnostic Error Messages

None.

Exit status

Always returns 0.

Known bugs

None.

See also

Program nameDescription
fuzznucNucleic acid pattern search
fuzztranProtein pattern search after translation
marscanFinds MAR/SAR sites in nucleic sequences

Other EMBOSS programs allow you to search for simple patterns and may be easier for the user who has never used regular expressions before:

Author(s)

This application was written by Peter Rice (pmr@sanger.ac.uk) Informatics Division, The Sanger Centre, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, UK.

History

Written (1999) - Peter Rice.

Target users

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

Comments