Using the metallopdb() function
<?php
include 'slides/mdb/scripts/mdb_tests.cfg';
$metal = 'zn';
$format = 'rss';
$mode = 'random';
$func = 'metallopdb';
$count = 5;
$getstr = MDB_SERVER.API_URI;
$getstr .= "?func=$func&metal=$metal";
$getstr .= "&mode=$mode&count=$count&format=$format";
$result = implode("",file($getstr));

echo "<h1 align='center'>Testing the HTTP based API</h1>
<b>Server used:</b> [ ".MDB_SERVER.
"]<br><b>Service:</b>[ ".API_URI."]
<hr>
<h2>Retrieving $count random zinc containing proteins</h2>
<b>Function vars:</b><br>
[metal: $metal]
[count: $count]
[format: $format]
[mode: $mode]
<br><b>Using the URL: </b>".
wordwrap($getstr,45,"<br>\n",true).
"<br><b>RESULT</b><br>
<pre>\n";
echo htmlspecialchars($result)."\n</pre>\n";
?>
Output

Testing the HTTP based API

Server used: [ http://metallo.scripps.edu:80]
Service:[ /services/api.php]

Retrieving 5 random zinc containing proteins

Function vars:
[metal: zn] [count: 5] [format: rss] [mode: random]
Using the URL: http://metallo.scripps.edu:80/services/api.ph
p?func=metallopdb&metal=zn&mode=random&count=
5&format=rss
RESULT
<?xml version="1.0" encoding="iso-8859-1"?>
<rdf:RDF 
         xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
         xmlns="http://purl.org/rss/1.0/"
         xmlns:mn="http://usefulinc.com/rss/manifest/"
         xmlns:dc="http://purl.org/dc/elements/1.1/"
>

  <channel rdf:about="http://metallo.scripps.edu/services/api.php?func=metallopdb&amp;metal=zn&amp;mode=random&amp;count=5&amp;format=rss">
    <title>MDB - The Metalloprotein Database and Browser</title>
    <link>http://metallo.scripps.edu</link>
    <description>Data retrieved using the MDB API</description>
    <items>
      <rdf:Seq>
        <rdf:li rdf:resource="http://metallo.scripps.edu/services/remote/remote.php?source_id[]=1b55&amp;metal[]=zn" />
        <rdf:li rdf:resource="http://metallo.scripps.edu/services/remote/remote.php?source_id[]=1bt7&amp;metal[]=zn" />
        <rdf:li rdf:resource="http://metallo.scripps.edu/services/remote/remote.php?source_id[]=1dcq&amp;metal[]=zn" />
        <rdf:li rdf:resource="http://metallo.scripps.edu/services/remote/remote.php?source_id[]=1htb&amp;metal[]=zn" />
        <rdf:li rdf:resource="http://metallo.scripps.edu/services/remote/remote.php?source_id[]=1znb&amp;metal[]=zn" />
      </rdf:Seq>
    </items>
  </channel>

  <item rdf:about="http://metallo.scripps.edu/services/remote/remote.php?source_id[]=1b55&amp;metal[]=zn">
    <link>http://metallo.scripps.edu/services/remote/remote.php?source_id[]=1b55&amp;metal[]=zn</link>
    <title>(Zn) 1b55 [deposited on: 1999/01/12, revised on: 1999/06/15]</title>
    <description>Header: [transferase 12-jan-99 1b55]
Title: [ph domain from bruton's tyrosine kinase in complex with inositol 1,3,4,5-tetrakisphosphate]
Compound: [mol_id: 1; molecule: tyrosine-protein kinase btk; chain: a, b; fragment: ph domain and btk motif; synonym: bruton's agammaglobulinemia tyrosine kinase, btk; ec: 2.7.1.112; engineered: yes; other_details: complex with inositol 1,3,4,5-tetrakisphosphate]
Source: [mol_id: 1; organism_scientific: homo sapiens; organism_common: human; cell: b-lymphocyte; expression_system: escherichia coli; expression_system_strain: bl21 (de3); expression_system_vector: pbat4; expression_system_plasmid: pbat4-btk3]
Keywords: [ph domain, btk motif, zinc binding, x-linked agammaglobulinemia, tyrosine-protein kinase, inositol 1,3,4,5-tetrakisphosphate] Authors[k.djinovic carugo,e.baraldi,m.hyvoenen,p.lo surdo, a.m.riley,b.v.l.potter,r.o'brien,j.e.ladbury,m.saraste] ExpData[x-ray diffraction] R-value[0.23] Resolution[2.40]</description>
  </item>

  <item rdf:about="http://metallo.scripps.edu/services/remote/remote.php?source_id[]=1bt7&amp;metal[]=zn">
    <link>http://metallo.scripps.edu/services/remote/remote.php?source_id[]=1bt7&amp;metal[]=zn</link>
    <title>(Zn) 1bt7 [deposited on: 1998/09/01, revised on: 1999/06/22]</title>
    <description>Header: [hydrolase 01-sep-98 1bt7]
Title: [the solution nmr structure of the n-terminal protease domain of the hepatitis c virus (hcv) ns3-protein, from bk strain, 20 structures]
Compound: [mol_id: 1; molecule: ns3 serine protease; chain: null; engineered: yes; mutation: ins(r180-askkkk); other_details: compound engineered adding a solubilising tail at the c-terminus]
Source: [mol_id: 1; organism_scientific: human hepatitis c virus; strain: bk; expression_system: escherichia coli; expression_system_strain: bl21 (de3); expression_system_plasmid: pt7.7]
Keywords: [viral non-structural protein, serine protease] Authors[g.barbato,d.o.cicero,m.c.nardi,c.steinkuhler,r.cortese, r.de francesco,r.bazzo] ExpData[nmr, 20 structures] R-value[] Resolution[]</description>
  </item>

  <item rdf:about="http://metallo.scripps.edu/services/remote/remote.php?source_id[]=1dcq&amp;metal[]=zn">
    <link>http://metallo.scripps.edu/services/remote/remote.php?source_id[]=1dcq&amp;metal[]=zn</link>
    <title>(Zn) 1dcq [deposited on: 1999/11/05, revised on: 1999/12/22]</title>
    <description>Header: [metal binding protein 05-nov-99 1dcq]
Title: [crystal structure of the arf-gap domain and ankyrin repeats of papbeta.]
Compound: [mol_id: 1; molecule: pyk2-associated protein beta; chain: a; fragment: arf-gap domain; engineered: yes]
Source: [mol_id: 1; organism_scientific: mus musculus; organism_common: mouse; organ: brain; expression_system: escherichia coli; expression_system_common: bacteria; expression_system_vector_type: plasmid; expression_system_plasmid: pet21a]
Keywords: [ankyrin repeats, metal binding protein] Authors[v.mandiyan,j.andreev,j.schlessinger,s.r.hubbard] ExpData[x-ray diffraction] R-value[0.21] Resolution[2.10]</description>
  </item>

  <item rdf:about="http://metallo.scripps.edu/services/remote/remote.php?source_id[]=1htb&amp;metal[]=zn">
    <link>http://metallo.scripps.edu/services/remote/remote.php?source_id[]=1htb&amp;metal[]=zn</link>
    <title>(Zn) 1htb [deposited on: 1995/08/10, revised on: 1995/12/07]</title>
    <description>Header: [oxidoreductase 10-aug-95 1htb]
Title: [crystallization of human beta3 alcohol dehydrogenase (10 mg/ml) in 100 mm sodium phosphate (ph 7.5), 7.5 mm nad+ and 1 mm 4-iodopyrazole at 25 c]
Compound: [mol_id: 1; molecule: beta3 alcohol dehydrogenase; chain: a, b; synonym: beta3 adh; ec: 1.1.1.1; engineered: yes; heterogen: nad+; heterogen: 4-iodopyrazole; other_details: homodimeric with one nad+ and one 4-iodopyrazole per subunit]
Source: [mol_id: 1; synthetic: yes; organism_scientific: homo sapiens; organism_common: human; organ: liver; expression_system: escherichia coli; expression_system_plasmid: pkk223-3; expression_system_gene: human beta3 cdna]
Keywords: [] Authors[t.d.hurley,g.j.davis] ExpData[x-ray diffraction] R-value[0.18] Resolution[2.40]</description>
  </item>

  <item rdf:about="http://metallo.scripps.edu/services/remote/remote.php?source_id[]=1znb&amp;metal[]=zn">
    <link>http://metallo.scripps.edu/services/remote/remote.php?source_id[]=1znb&amp;metal[]=zn</link>
    <title>(Zn) 1znb [deposited on: 1996/06/06, revised on: 1997/01/11]</title>
    <description>Header: [hydrolase (beta-lactamase) 06-jun-96 1znb]
Title: [metallo-beta-lactamase]
Compound: [mol_id: 1; molecule: metallo-beta-lactamase; chain: a, b; synonym: class b beta-lactamase; ec: 3.5.2.6; engineered: yes]
Source: [mol_id: 1; organism_scientific: bacteroides fragilis; strain: tal3636; variant: clinical isolate qmcn3; expression_system: escherichia coli; expression_system_strain: bl21; expression_system_plasmid: lambda de3; expression_system_gene: ccra3]
Keywords: [metallo beta-lactamase zinc] Authors[n.o.concha,o.herzberg] ExpData[x-ray diffraction] R-value[0.17] Resolution[1.85]</description>
  </item>

  <rdf:Description rdf:ID="manifest">
    <mn:channels>
      <rdf:Seq>
        <rdf:li rdf:resource="http://metallo.scripps.edu/services/api.php?func=metallopdb&amp;metal=zn&amp;mode=random&amp;count=5&amp;format=rss" />
      </rdf:Seq>
    </mn:channels>
  </rdf:Description>

</rdf:RDF>