Table 1.

Overview of GSP resources

	PPI Resources	Number of.PPI pairs	Number of proteins in PPI pairs
GSP PPI	[1] Literatures from PubMed	1259	740
	[2] InAct	1528	677
	[3] BIND	1475	538
	[4] TAIR	1073	698
	[1]∼[4]	3866	1875
Protein complexes	[5] KEGG (enzyme complex)	1700	856
Total	[1]∼[5]	4666	2285

[1] Manually collected protein interactions are extracted directly from thousands of published articles in PubMed. [2] InAct provides a freely available, open source database system for protein interaction data in EMBL-EBI. All interactions are derived from literature curation or direct user submissions. [3] BIND is a new resource to perform cross-database searches of available sequence, interaction, complex and pathway information. It integrates a range of component databases including Genbank and BIND, the Biomolecular Interaction Network Database. [4] TAIR provides ‘Tair Protein Interaction’ file by Matt Geisler at its FTP (ftp://ftp.arabidopsis.org/home/tair/Proteins/). [5] KEGG, a reference knowledge base linking genomes to biological systems and environments, provides resourceful enzyme complex information. [1]∼[4] After mapping various symbols to AGI, we found 3866 PPI pairs involving 1875 proteins with literature supports. [1]∼[5] combined with enzyme complexes from KEGG, the total number of GSP is up to 4666 involving with 2285 proteins.