after visit Mackay memorial hospital (in Taiwan)
I done some research on Database of Interacting Proteins (DIP)
ex: I want to know what proteins interact with P53
enter P53 in NodeID or Name field in this page
you will get DIP nodes for p53 in human and mouse
(DIP:368N, DIP:369N, DIP:5978N, DIP:24202N, etc)
in each DIP node, you can click on the "graph" link at top right corner
you'll see what other proteins interact with P53.

it also provides links to related information in
PDB, NCBI, Prosite, Smart, InterPro databases.

another one similar to this