<p>I wonder why I can't find any database for enzymes composed by multiple proteins as separate entities.</p>

<p>I'll explain better: the OST complex is a multiple-units enzyme composed by 6-7 proteins, like OST4, STT3A or STT3B, RPN1, DAD1, etc...
If I look for any of these proteins in Uniprot, I get a nice entry for each: for example, if you look at STT3A you get a lot of informations, including a description that explains that this protein partecipates to the OST complex.</p>

<p>However, if you look for 'OST complex' in uniprot, there is not a separate entity for this multiple-units enzyme... I wonder if you know of a database where complex enzymes are described, or if you have faced this problem before.</p>

<p>Does this one help?  <a href="http://mips.helmholtz-muenchen.de/genre/proj/corum/index.html">CORUM</a> – the Comprehensive Resource of Mammalian protein complexes.</p>
<p>Just tried a quick search using "DAD1" and it seemed to return useful results.</p>