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Guidelines for PSI Target Proposals

Individual researchers can submit target nominations to the PSI centers. Investigators agree to adhere to the following guidelines when preparing their target proposals.


  1. Targets that are nominated by the community should be consistent with the overall mission of the PSI. Priority will be granted to novel targets with less than 30% identity to any other structure deposited in the PDB.
  2. All coordinates for nominated targets, including any nominations from for-profit organizations, will be deposited for immediate release within 4 weeks of structure completion. All clones leading to successful structures will be deposited in the PSI Materials Repository. It is expected that the investigators submitting nominations will make every effort to submit publications based on the PSI work.
  3. When targets are proposed, a rationale for why these targets should be studied must be briefly outlined, and whether any previous work has been performed on these targets. It is important to provide full sequence information, as well as any constructs that have been attempted for protein production and/or crystallization. Recommendations as to whether this would be a target for a production center or a specialized center would also be useful, and whether X-ray or NMR is more suitable. It may be prudent to contact one of the centers for guidance before submission especially if you have any questions, particularly about general feasibility or appropriate methodologies. Nominations from foreign investigators are encouraged to consult with the PSI Center Director prior to nomination.
  4. It is important that any targets that are taken on by the PSI have at least the same chance of success as the targets that are already in the overall pipelines of communal targets chosen by the PSI itself. The goal is to provide useful structures to the community with a reasonable success rate, so that the PSI can contribute substantially to the community efforts.
  5. Targets which would not normally be within the mission of the PSI would be those that have high sequence identity to other targets in the PDB and structure determination of complexes of known targets. Exceptions could be made in some instances for particularly high value targets for which it has been difficult to achieve success despite the high sequence homology to known structures, and complexes between proteins of known structure with proteins of unknown structures, or for those of exceptionally high biomedical relevance.
  6. If protein samples are provided by the nominator, then the protocols used for sample production must be well documented and would normally include expression system, purity, stability, buffers and whether the protein can be concentrated to at least 5-10 mg/ml for crystallization studies. Similar sets of feasibility criteria, including demonstration of sample stability and high quality HSQC spectra, would pertain to targets proposed for NMR study.
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