Parsing Pdb To Find Taxonomy Information Of Chains

Question

[Will]

I'm trying to find examples of crystal structures where "cross-species" interactions are being represented. A few examples are 2R03, 3DCG, 1ZLA. My thought was to parse the PDB files and find instances where the "Source" of each polymer is different. I know this will produce plenty of false-positives but it should hopefully be good against false-negatives.

The problem I'm having is that I can't find the "Source" information in any of the downloadable file formats (in the ftp-data directory).

Does anyone know where this information is stored? I would prefer not to resort to HTML scraping of the search page ... but I will if needed.

Thanks

Answer 1

[Khader Shameer]

Individual protein chain level taxonomy information is available from SIFTS.

Please check the pdb_chain_taxonomy.lst

PDB CHAIN   TAX_ID      MOLECULE_TYPE       SCIENTIFIC_NAME
101m    A   9755        PROTEIN         Physeter catodon
102l    A   10665       PROTEIN         Enterobacteria phage T4
102m    A   9755        PROTEIN         Physeter catodon
103d    A           NUCLEIC ACID            
103d    B           NUCLEIC ACID            
103l    A   10665       PROTEIN         Enterobacteria phage T4
103m    A   9755        PROTEIN         Physeter catodon
104d    A           UNKNOWN         
104d    B           UNKNOWN         
104l    A   10665       PROTEIN         Enterobacteria phage T4
104l    B   10665       PROTEIN         Enterobacteria phage T4

Answer 2

[Leonor Palmeira]

By briefly searching the PDB ftp site, I found that in the gzipped files stored in these directories, there is a SOURCE line containing the organism:

ftp://ftp.wwpdb.org/pub/pdb/data/structures/divided/pdb/

These gzipped files can also be found here: ftp://ftp.wwpdb.org/pub/pdb/data/structures/all/pdb/

Does this help?

Answer 3

[Pierre Lindenbaum]

The following XSLT stylesheet extracts the content of a PDB XML record:

<xsl:stylesheet version="1.0" xmlns:xsl="&lt;a href=" http:="" www.w3.org="" 1999="" XSL="" Transform"="" rel="nofollow">http://www.w3.org/1999/XSL/Transform"
    xmlns:PDBx="http://pdbml.pdb.org/schema/pdbx-v40.xsd"
    xmlns="http://pdbml.pdb.org/schema/pdbx-v40.xsd"
    >
<xsl:output method="text"/>

<xsl:template match="/">
<xsl:variable name="name" select="PDBx:datablock/@datablockName"/>
<xsl:text>#name genus   scientific_name taxonid
</xsl:text>
 <xsl:for-each select="/PDBx:datablock/PDBx:entity_src_genCategory/PDBx:entity_src_gen">
    <xsl:value-of select="$name"/>
        <xsl:text>  </xsl:text>
        <xsl:value-of select="PDBx:gene_src_genus"/>
        <xsl:text>  </xsl:text>
        <xsl:value-of select="PDBx:pdbx_gene_src_scientific_name"/>
        <xsl:text>  </xsl:text>
        <xsl:value-of select="PDBx:pdbx_gene_src_ncbi_taxonomy_id"/>
        <xsl:text>
</xsl:text>
    </xsl:for-each>
</xsl:template>

</xsl:stylesheet>

eg. with 3DCG

$ xsltproc stylesheet.xsl "http://www.pdb.org/pdb/download/downloadFile.do?fileFormat=xml&compression=NO&structureId=3DCG"
#name   genus   scientific_name taxonid
3DCG        Homo sapiens    9606
3DCG        Homo sapiens    9606
3DCG        Human immunodeficiency virus type 1 (NEW YORK-5 ISOLATE)    11698