Critical Assessment of Techniques for Protein Structure Prediction (CASP) are community experiments that aim to advance the state of the art in protein structure modeling. Every other year since 1994, CASP collects information on soon-to-be released experimental structures, passes on sequence data to the structure modeling community, and collects blind predictions of structure for assessment. About 100 modeling groups from around the world have participated. Results of CASP experiments are published in special issues of the journal Proteins (e.g., CASP12).
The success of CASP depends on the generosity of the structure determination community. We are now requesting targets for CASP13 experiment, which will launch at the beginning of May. The CASP community needs modeling targets over a wide range of difficulty, for modeling with and without the aid of templates. X-ray, NMR and cryo-EM structures are all welcome, with particular interest in membrane proteins, protein complexes, and cryo-EM structures. We are also extending CASP to include more modeling efforts assisted by sparse experimental data, in collaboration with experimental groups working within NMR, SAXS, SANS, crosslinking, and FRET techniques for which protein material is needed (of course this is not expected for most targets, but if available, it would be much appreciated!).
So, if you have anything suitable, we encourage you to mark your PDB deposition as a "CASP target" in wwPDB's OneDep deposition system. Alternatively, you can suggest your protein to CASP directly through the CASP13 target entry page.
For those of you who have not provided targets to CASP before, the procedure is simple and fast. We do not need the structure in advance of its PDB release, and if we are notified early enough (at least of three weeks before release, more is better) there need be no delay in structure release. More details are available.
CASP target providers are regularly invited to contribute to special issue papers, for example:
2018: Kryshtafovych A, Albrecht R, Baslé A, Bule P, Caputo AT, Carvalho AL, Chao KL, Diskin R, Fidelis K, Fontes CMGA, Fredslund F, Gilbert HJ, Goulding CW, Hartmann MD, Hayes CS, Herzberg O, Hill JC, Joachimiak A, Kohring GW, Koning RI, Lo Leggio L, Mangiagalli M, Michalska K, Moult J, Najmudin S, Nardini M, Nardone V, Ndeh D, Nguyen TH, Pintacuda G, Postel S, van Raaij MJ, Roversi P, Shimon A, Singh AK, Sundberg EJ, Tars K, Zitzmann N, Schwede T. (2018). Target highlights from the first post-PSI CASP experiment (CASP12, May-August 2016). Proteins 86 (S1), 27-50. doi: 10.1002/prot.25392. PMID: 28960539
2016: Kryshtafovych A, Moult J, Baslé A, Burgin A, Craig TK, Edwards RA, Fass D, Hartmann MD, Korycinski M, Lewis RJ, Lorimer D, Lupas AN, Newman J, Peat TS, Piepenbrink KH, Prahlad J, van Raaij MJ, Rohwer F, Segall AM, Seguritan V, Sundberg EJ, Singh AK, Wilson MA, Schwede T. (2016). Some of the most interesting CASP11 targets through the eyes of their authors. Proteins 84 (S1), 34-50. doi: 10.1002/prot.24942. PMID: 26473983
2014: Kryshtafovych A, Moult J, Bales P, Bazan JF, Biasini M, Burgin A, Chen C, Cochran FV, Craig TK, Das R, Fass D, Garcia-Doval C, Herzberg O, Lorimer D, Luecke H, Ma X, Nelson DC, van Raaij MJ, Rohwer F, Segall A, Seguritan V, Zeth K, Schwede T. (2014). Challenging the state-of-the-art in protein structure prediction: Highlights of experimental target structures for the 10th critical assessment of techniques for protein structure prediction experiment CASP10. Proteins 82 (S2), 26-42. doi: 10.1002/prot.24489. PMID: 24318984
2011: Kryshtafovych A, Moult J, Bartual SG, Bazan JF, Berman H, Casteel DE, Christodoulou E, Everett JK, Hausmann J, Heidebrecht T, Hills T, Hui R, Hunt JF, Seetharaman J, Joachimiak A, Kennedy MA, Kim C, Lingel A, Michalska K, Montelione GT, Otero JM, Perrakis A, Pizarro JC, van Raaij MJ, Ramelot TA, Rousseau F, Tong L, Wernimont AK, Young J, Schwede T. (2011). Target highlights in CASP9: Experimental target structures for the critical assessment of techniques for protein structure prediction. Proteins 79 (S10), 6-20. doi: 10.1002/prot.23196. PMID: 22020785
Thanks, CASP organizing committee: John Moult, University of Maryland, USA Krzysztof Fidelis, University of California, Davis, USA Andriy Kryshtafovych, University of California, Davis, USA Torsten Schwede, University of Basel, Switzerland
Get in touch: firstname.lastname@example.org More information: http://www.predictioncenter.org/casp13/index.cgi Submit a target: http://www.predictioncenter.org/casp13/targets_submission.cgi
Validation reports for all PDB structures have been updated to include new percentile statistics reflecting the state of the archive on December 31st 2017 and updated versions of third-party software: CCP4/Refmac (7.0 v44), Phenix (1.13) and Mogul (2018) and CSD archive (as539be). The LLDF statistic previously used to identify ligands that do not fit electron density well has been replaced by a combination of Real-space R-factor (RSR>0.4) and Real-space correlation coefficient (RSCC<0.8). The identification of standard amino acid or nucleotide residues that do not fit the electron density well has been corrected to take into account how reliably Refmac software reproduces the R-factors reported by authors. Documentation at wwpdb.org/validation has been updated to reflect these changes.
Updated reports are accessible from:
A copy of the previous version is archived at RCSB PDB and PDBj.
wwPDB validation reports provide an assessment of structure quality using widely accepted standards and criteria, recommended by community experts serving in Validation Task Forces. The wwPDB partners strongly encourage journal editors and referees to request them from authors as part of the manuscript submission and review process. The reports are date-stamped and display the wwPDB logo, and contain the same information, regardless of which wwPDB site processed the entry. Provision of wwPDB validation reports is already required by Nature, eLife, The Journal of Biological Chemistry, the International Union of Crystallography (IUCr) journals, FEBS journals, Journal of Immunology and Angew Chem Int Ed Engl as part of their manuscript-submission process.
Validation reports are also provided to depositors through OneDep validation, deposition and biocuration of structure data. The wwPDB partners encourage the use of the stand-alone validation server and the web service API at any time prior to data deposition. Depositors are required to review and accept the reports as part of the data submission process. Validation reports will continue to be developed and improved as we receive recommendations from the expert Validation Task Forces for X-ray, NMR, EM, experts on ligand validation, and as we collect feedback from depositors and users.
An article focused on the structure validation reports produced by wwPDB is available: Validation of Structures in the Protein Data Bank (2017) Structure 25: 1916-1927 doi: 10.1016/j.str.2017.10.009.
The journal Database has published an article describing Worldwide Protein Data Bank biocuration supporting open access to high-quality 3D structural biology data.
All data deposited to the PDB undergo critical review by wwPDB biocurators. Structural data submitted are examined for self-consistency, standardized using controlled vocabularies, cross-referenced with other biological data resources, and validated for scientific/technical accuracy.
Biocuration is integral to PDB data archiving, as it facilitates accurate, consistent, and comprehensive representation of biomolecular structure data, which in turn allows efficient and effective usage by research scientists, educators, students, and the curious public worldwide.
This paper describes the importance of biocuration for structural biology data deposited to the PDB, wwPDB biocuration processes, and the role of expert biocurators in sustaining a high-quality archive.
Worldwide Protein Data Bank biocuration supporting open access to high-quality 3D structural biology data Jasmine Y. Young, John D. Westbrook, Zukang Feng, Ezra Peisach, Irina Persikova, Raul Sala, Sanchayita Sen, John M. Berrisford, G. Jawahar Swaminathan, Thomas J. Oldfield, Aleksandras Gutmanas, Reiko Igarashi, David R. Armstrong, Kumaran Baskaran, Li Chen, Minyu Chen, Alice R. Clark, Luigi Di Costanzo, Dimitris Dimitropoulos, Guanghua Gao, Sutapa Ghosh, Swanand Gore, Vladimir Guranovic, Pieter M. S. Hendrickx, Brian P. Hudson, Yasuyo Ikegawa, Yumiko Kengaku, Catherine L. Lawson, Yuhe Liang, Lora Mak, Abhik Mukhopadhyay, Buvaneswari Narayanan, Kayoko Nishiyama, Ardan Patwardhan, Gaurav Sahni, Eduardo Sanz-García, Junko Sato, Monica R. Sekharan, Chenghua Shao, Oliver S. Smart, Lihua Tan, Glen van Ginkel, Huanwang Yang, Marina A. Zhuravleva, John L. Markley, Haruki Nakamura, Genji Kurisu, Gerard J. Kleywegt, Sameer Velankar, Helen M. Berman, Stephen K. Burley (2018) Database 2018: bay002 doi: 10.1093/database/bay002
A snapshot of the PDB archive (ftp://ftp.wwpdb.org) as of January 1, 2018 has been added to ftp://snapshots.wwpdb.org and ftp://snapshots.pdbj.org. Snapshots have been archived annually since January 2005 to provide readily identifiable data sets for research on the PDB archive.
The directory 20180101 includes the 136,472 experimentally-determined structure and experimental data available at that time. Atomic coordinate and related metadata are available in PDBx/mmCIF, PDB, and XML file formats. The date and time stamp of each file indicates the last time the file was modified. The snapshot is 1034 GB.