getgenbank

Retrieve sequence information from GenBank database

Syntax

Data = getgenbank(AccessionNumber) getgenbank(AccessionNumber) Data = getgenbank(..., 'PartialSeq', PartialSeqValue, ...) Data = getgenbank(..., 'ToFile', ToFileValue, ...) Data = getgenbank(..., 'FileFormat', FileFormatValue, ...) Data = getgenbank(..., 'SequenceOnly', SequenceOnlyValue, ...)

Arguments

`AccessionNumber`	Character vector or string specifying a unique alphanumeric identifier for a sequence record.
`PartialSeqValue`	Two-element array of integers containing the start and end positions of the subsequence `[StartBP, EndBP]` that specifies a subsequence to retrieve. `StartBP` is an integer between 1 and `EndBP`. `EndBP` is an integer between `StartBP` and the length of the sequence.
`ToFileValue`	Character vector or string specifying either a file name or a path and file name for saving the GenBank^® data. If you specify only a file name, the file is saved to the MATLAB^® Current Folder.
`FileFormatValue`	Character vector or string specifying the format for the sequence information. Choices are: `'GenBank'` — Default when `SequenceOnlyValue` is `false`. `'FASTA'` — Default when `SequenceOnlyValue` is `true`. When `'FASTA'`, then `Data` contains only two fields, `Header` and `Sequence`.
`SequenceOnlyValue`	Controls the return of only the sequence as a character array. Choices are `true` or `false` (default).

Description

getgenbank retrieves nucleotide information from the GenBank database. This database is maintained by the National Center for Biotechnology Information (NCBI). For more details about the GenBank database, see

https://www.ncbi.nlm.nih.gov/Genbank/

Data = getgenbank(AccessionNumber) searches for the accession number in the GenBank database and returns Data, a MATLAB structure containing information for the sequence.

Tip

If an error occurs while retrieving the GenBank-formatted information, try rerunning the query. Errors can occur due to Internet connectivity issues that are unrelated to the GenBank record.

getgenbank(AccessionNumber) displays information in the MATLAB Command Window without returning data to a variable. The displayed information is only hyperlinks to the URLs used to search for and retrieve the data.

getgenbank(..., 'PropertyName', PropertyValue, ...) calls getgenbank with optional properties that use property name/property value pairs. You can specify one or more properties in any order. Each PropertyName must be enclosed in single quotation marks and is case insensitive. These property name/property value pairs are as follows:

Data = getgenbank(..., 'PartialSeq', PartialSeqValue, ...) returns the specified subsequence in the Sequence field of the MATLAB structure. PartialSeqValue is a two-element array of integers containing the start and end positions of the subsequence [StartBP, EndBP]. StartBP is an integer between 1 and EndBP. EndBP is an integer between StartBP and the length of the sequence.

Data = getgenbank(..., 'ToFile', ToFileValue, ...) saves the data returned from the GenBank database to a file. ToFileValue is a character vector or string specifying either a file name or a path and file name for saving the GenBank data. If you specify only a file name, the file is saved to the MATLAB Current Folder. The function does not append data to an existing file. Instead, it overwrites the contents of the existing file without warning.

Tip

You can read a GenBank-formatted file back into MATLAB using the genbankread function.

Data = getgenbank(..., 'FileFormat', FileFormatValue, ...) returns the sequence in the specified format. Choices are 'GenBank' or 'FASTA'. When 'FASTA', then Data contains only two fields, Header and Sequence. 'GenBank' is the default when SequenceOnlyValue is false. 'FASTA' is the default when SequenceOnlyValue is true.

Data = getgenbank(..., 'SequenceOnly', SequenceOnlyValue, ...) returns only the sequence in Data, a character array. Choices are true or false (default).

Note

If you use the 'SequenceOnly' and 'ToFile' properties together, the output is always a FASTA-formatted file.

Examples

Example 26. Retrieving an RNA Sequence

To retrieve the sequence from chromosome 19 that codes for the human insulin receptor and store it in a structure, S, in the MATLAB Command Window, type:

S = getgenbank('M10051')

S = 

                LocusName: 'HUMINSR'
      LocusSequenceLength: '4723'
     LocusNumberofStrands: ''
            LocusTopology: 'linear'
        LocusMoleculeType: 'mRNA'
     LocusGenBankDivision: 'PRI'
    LocusModificationDate: '06-JAN-1995'
               Definition: 'Human insulin receptor mRNA, complete cds.'
                Accession: 'M10051'
                  Version: 'M10051.1'
                       GI: '186439'
                  Project: []
                   DBLink: []
                 Keywords: 'insulin receptor; tyrosine kinase.'
                  Segment: []
                   Source: 'Homo sapiens (human)'
           SourceOrganism: [4x65 char]
                Reference: {[1x1 struct]}
                  Comment: [14x67 char]
                 Features: [51x74 char]
                      CDS: [1x1 struct]
                 Sequence: [1x4723 char]
                SearchURL: [1x67 char]
              RetrieveURL: [1x101 char]

Example 27. Retrieving a Partial RNA Sequence

By looking at the Features field of the structure returned, you can determine that the coding sequence is positions 139 through 4287. To retrieve only the coding sequence from chromosome 19 that codes for the human insulin receptor and store it in a structure, CDS, in the MATLAB Command Window, type:

CDS = getgenbank('M10051','PARTIALSEQ',[139,4287]);

Compatibility Considerations

expand all

Appending data to existing file

Behavior changed in R2019a

The function no longer appends data to an existing file. The function now overwrites the contents of the existing file without warning.

Documentation