Call to structural biologists working on structures of protein complexes

This is a call to structural biologists working on structures of protein complexes, to consider offering their structures as targets to CAPRI, the community wide initiative for the Critical Assessment of Predicted Interactions.

As you may know, CAPRI is a double-blind experiment established 15 years ago for assessing the performance of computational methods for modelling protein-protein interactions and protein complexes. CAPRI has played an important role in establishing these methods as a useful tool for helping to populate the still poorly charted landscape of protein assemblies. It has done so by offering computational biologists (an average of 50 groups from around the world participating in CAPRI Rounds each year) the opportunity to test their algorithms in blind predictions of experimentally determined 3D structures of protein complexes, the ‘targets’, provided to CAPRI prior to publication.

Complexes that qualify as targets for CAPRI must be structures (determined using x-ray crystallography, NMR or high resolution Cryo-EM) that have not yet been published or publicly described in the literature or the Internet. They must be complexes (dimers of higher order assemblies) where the protein moiety is bound to another protein, to an oligo peptide, to nucleic acids (DNA or RNA), oligosaccharides or lipids. Protein assemblies comprising identical subunits (homo-oligomers) also qualify. A CAPRI prediction Round is initiated each time a target (or a few targets) become available, and completed three to six weeks later. Offering your complex as a target for CAPRI should not delay publication, provided the target is offered just before the paper describing it is submitted. You may also be assured that target information is kept strictly confidential until specified otherwise by you, the author.

Over 40 structural biologists worldwide have offered targets to CAPRI in the past, with some doing so repeatedly. They have been personally acknowledged and cited in all CAPRI publications describing prediction results (see the 6 CAPRI Special Issues of Proteins). More than once, these results have also contributed new insights into the biological function of the corresponding complexes. They therefore hope that you will join their rank.

In case you are interested in offering a target, or think a colleague of yours might be, or have any questions concerning your participation in CAPRI, please contact: Shoshana Wodak or

For the CAPRI Management Committee Prof. Shoshana J. Wodak, VIB Structural Biology research Centre, VUB, Building E Pleinlaan 2, 1050 Brussels, BELGIUM