An Second-generation Protein-Protein Interaction Network of Helicobacter pylori

Helicobacter pylori infections cause gastric ulcers and play a major role in the development of gastric cancer. In 2001 the first protein interactome was published for this species, revealing over 1,500 binary protein interactions resulting from 261 yeast two-hybrid (Y2H) screens. Here we roughly double the number of previously published interactions using an ORFeome-based, proteome-wide Y2H screening strategy. We identified a total of 1,515 protein-protein interactions, of which 1,461 are new. The integration of all the interactions reported in H. pylori results in 3,004 unique interactions with a proteome connectivity of ~70%. Using various filtering techniques we derived from our new data a core network consisting of 908 interactions. We compared our dataset to several other bacterial interactomes and experimentally benchmarked the conservation of interactions using 365 protein pairs (interologs) of E. coli of which one third turned out to be conserved in both species.