1
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Kryshtafovych A, Rigden DJ. To split or not to split: CASP15 targets and their processing into tertiary structure evaluation units. Proteins 2023; 91:1558-1570. [PMID: 37254889 PMCID: PMC10687315 DOI: 10.1002/prot.26533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 05/02/2023] [Accepted: 05/18/2023] [Indexed: 06/01/2023]
Abstract
Processing of CASP15 targets into evaluation units (EUs) and assigning them to evolutionary-based prediction classes is presented in this study. The targets were first split into structural domains based on compactness and similarity to other proteins. Models were then evaluated against these domains and their combinations. The domains were joined into larger EUs if predictors' performance on the combined units was similar to that on individual domains. Alternatively, if most predictors performed better on the individual domains, then they were retained as EUs. As a result, 112 evaluation units were created from 77 tertiary structure prediction targets. The EUs were assigned to four prediction classes roughly corresponding to target difficulty categories in previous CASPs: TBM (template-based modeling, easy or hard), FM (free modeling), and the TBM/FM overlap category. More than a third of CASP15 EUs were attributed to the historically most challenging FM class, where homology or structural analogy to proteins of known fold cannot be detected.
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Affiliation(s)
| | - Daniel J. Rigden
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, England
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2
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Monroe L, Kihara D. Using steered molecular dynamic tension for assessing quality of computational protein structure models. J Comput Chem 2022; 43:1140-1150. [PMID: 35475517 DOI: 10.1002/jcc.26876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 02/16/2022] [Accepted: 04/15/2022] [Indexed: 11/12/2022]
Abstract
The native structures of proteins, except for notable exceptions of intrinsically disordered proteins, in general take their most stable conformation in the physiological condition to maintain their structural framework so that their biological function can be properly carried out. Experimentally, the stability of a protein can be measured by several means, among which the pulling experiment using the atomic force microscope (AFM) stands as a unique method. AFM directly measures the resistance from unfolding, which can be quantified from the observed force-extension profile. It has been shown that key features observed in an AFM pulling experiment can be well reproduced by computational molecular dynamics simulations. Here, we applied computational pulling for estimating the accuracy of computational protein structure models under the hypothesis that the structural stability would positively correlated with the accuracy, i.e. the closeness to the native, of a model. We used in total 4929 structure models for 24 target proteins from the Critical Assessment of Techniques of Structure Prediction (CASP) and investigated if the magnitude of the break force, that is, the force required to rearrange the model's structure, from the force profile was sufficient information for selecting near-native models. We found that near-native models can be successfully selected by examining their break forces suggesting that high break force indeed indicates high stability of models. On the other hand, there were also near-native models that had relatively low peak forces. The mechanisms of the stability exhibited by the break forces were explored and discussed.
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Affiliation(s)
- Lyman Monroe
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Daisuke Kihara
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA.,Department of Computer Science, Purdue University, West Lafayette, Indiana, USA.,Purdue Center for Cancer Research, Purdue University, West Lafayette, Indiana, USA
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3
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Kinch LN, Schaeffer RD, Kryshtafovych A, Grishin NV. Target classification in the 14th round of the critical assessment of protein structure prediction (CASP14). Proteins 2021; 89:1618-1632. [PMID: 34350630 DOI: 10.1002/prot.26202] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 06/21/2021] [Accepted: 07/11/2021] [Indexed: 12/14/2022]
Abstract
An evolutionary-based definition and classification of target evaluation units (EUs) is presented for the 14th round of the critical assessment of structure prediction (CASP14). CASP14 targets included 84 experimental models submitted by various structural groups (designated T1024-T1101). Targets were split into EUs based on the domain organization of available templates and performance of server groups. Several targets required splitting (19 out of 25 multidomain targets) due in part to observed conformation changes. All in all, 96 CASP14 EUs were defined and assigned to tertiary structure assessment categories (Topology-based FM or High Accuracy-based TBM-easy and TBM-hard) considering their evolutionary relationship to existing ECOD fold space: 24 family level, 50 distant homologs (H-group), 12 analogs (X-group), and 10 new folds. Principal component analysis and heatmap visualization of sequence and structure similarity to known templates as well as performance of servers highlighted trends in CASP14 target difficulty. The assigned evolutionary levels (i.e., H-groups) and assessment classes (i.e., FM) displayed overlapping clusters of EUs. Many viral targets diverged considerably from their template homologs and thus were more difficult for prediction than other homology-related targets. On the other hand, some targets did not have sequence-identifiable templates, but were predicted better than expected due to relatively simple arrangements of secondary structural elements. An apparent improvement in overall server performance in CASP14 further complicated traditional classification, which ultimately assigned EUs into high-accuracy modeling (27 TBM-easy and 31 TBM-hard), topology (23 FM), or both (15 FM/TBM).
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Affiliation(s)
- Lisa N Kinch
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - R Dustin Schaeffer
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | | | - Nick V Grishin
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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4
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Kinch LN, Pei J, Kryshtafovych A, Schaeffer RD, Grishin NV. Topology evaluation of models for difficult targets in the 14th round of the critical assessment of protein structure prediction. Proteins 2021; 89:1673-1686. [PMID: 34240477 DOI: 10.1002/prot.26172] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 06/28/2021] [Accepted: 07/01/2021] [Indexed: 12/25/2022]
Abstract
This report describes the tertiary structure prediction assessment of difficult modeling targets in the 14th round of the Critical Assessment of Structure Prediction (CASP14). We implemented an official ranking scheme that used the same scores as the previous CASP topology-based assessment, but combined these scores with one that emphasized physically realistic models. The top performing AlphaFold2 group outperformed the rest of the prediction community on all but two of the difficult targets considered in this assessment. They provided high quality models for most of the targets (86% over GDT_TS 70), including larger targets above 150 residues, and they correctly predicted the topology of almost all the rest. AlphaFold2 performance was followed by two manual Baker methods, a Feig method that refined Zhang-server models, two notable automated Zhang server methods (QUARK and Zhang-server), and a Zhang manual group. Despite the remarkable progress in protein structure prediction of difficult targets, both the prediction community and AlphaFold2, to a lesser extent, faced challenges with flexible regions and obligate oligomeric assemblies. The official ranking of top-performing methods was supported by performance generated PCA and heatmap clusters that gave insight into target difficulties and the most successful state-of-the-art structure prediction methodologies.
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Affiliation(s)
- Lisa N Kinch
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Jimin Pei
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | | | - R Dustin Schaeffer
- Department of Biophysics and Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Nick V Grishin
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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5
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Jing X, Xu J. Improved Protein Model Quality Assessment By Integrating Sequential And Pairwise Features Using Deep Learning. Bioinformatics 2020; 36:5361-5367. [PMID: 33325480 PMCID: PMC8016469 DOI: 10.1093/bioinformatics/btaa1037] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 11/27/2020] [Accepted: 12/06/2020] [Indexed: 12/23/2022] Open
Abstract
MOTIVATION Accurately estimating protein model quality in the absence of experimental structure is not only important for model evaluation and selection, but also useful for model refinement. Progress has been steadily made by introducing new features and algorithms (especially deep neural networks), but the accuracy of quality assessment (QA) is still not very satisfactory, especially local QA on hard protein targets. RESULTS We propose a new single-model-based QA method ResNetQA for both local and global quality assessment. Our method predicts model quality by integrating sequential and pairwise features using a deep neural network composed of both 1 D and 2 D convolutional residual neural networks (ResNet). The 2 D ResNet module extracts useful information from pairwise features such as model-derived distance maps, co-evolution information, and predicted distance potential from sequences. The 1 D ResNet is used to predict local (global) model quality from sequential features and pooled pairwise information generated by 2 D ResNet. Tested on the CASP12 and CASP13 datasets, our experimental results show that our method greatly outperforms existing state-of-the-art methods. Our ablation studies indicate that the 2 D ResNet module and pairwise features play an important role in improving model quality assessment. AVAILABILITY https://github.com/AndersJing/ResNetQA. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Xiaoyang Jing
- Toyota Technological Institute at Chicago, Chicago, IL, 60637, USA
| | - Jinbo Xu
- Toyota Technological Institute at Chicago, Chicago, IL, 60637, USA
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6
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Karczyńska AS, Ziȩba K, Uciechowska U, Mozolewska MA, Krupa P, Lubecka EA, Lipska AG, Sikorska C, Samsonov SA, Sieradzan AK, Giełdoń A, Liwo A, Ślusarz R, Ślusarz M, Lee J, Joo K, Czaplewski C. Improved Consensus-Fragment Selection in Template-Assisted Prediction of Protein Structures with the UNRES Force Field in CASP13. J Chem Inf Model 2020; 60:1844-1864. [PMID: 31999919 PMCID: PMC7588044 DOI: 10.1021/acs.jcim.9b00864] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
The method for protein-structure
prediction, which combines the
physics-based coarse-grained UNRES force field with knowledge-based
modeling, has been developed further and tested in the 13th Community
Wide Experiment on the Critical Assessment of Techniques for Protein
Structure Prediction (CASP13). The method implements restraints from
the consensus fragments common to server models. In this work, the
server models to derive fragments have been chosen on the basis of
quality assessment; a fully automatic fragment-selection procedure
has been introduced, and Dynamic Fragment Assembly pseudopotentials
have been fully implemented. The Global Distance Test Score (GDT_TS),
averaged over our “Model 1” predictions, increased by
over 10 units with respect to CASP12 for the free-modeling category
to reach 40.82. Our “Model 1” predictions ranked 20
and 14 for all and free-modeling targets, respectively (upper 20.2%
and 14.3% of all models submitted to CASP13 in these categories, respectively),
compared to 27 (upper 21.1%) and 24 (upper 18.9%) in CASP12, respectively.
For oligomeric targets, the Interface Patch Similarity (IPS) and Interface
Contact Similarity (ICS) averaged over our best oligomer models increased
from 0.28 to 0.36 and from 12.4 to 17.8, respectively, from CASP12
to CASP13, and top-ranking models of 2 targets (H0968 and T0997o)
were obtained (none in CASP12). The improvement of our method in CASP13
over CASP12 was ascribed to the combined effect of the overall enhancement
of server-model quality, our success in selecting server models and
fragments to derive restraints, and improvements of the restraint
and potential-energy functions.
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Affiliation(s)
| | - Karolina Ziȩba
- Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, Gdańsk 80-308, Poland
| | - Urszula Uciechowska
- Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, Gdańsk 80-308, Poland
| | - Magdalena A Mozolewska
- Institute of Computer Science, Polish Academy of Sciences, ul. Jana Kazimierza 5, Warsaw PL-02668, Poland
| | - Paweł Krupa
- Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, Warsaw PL-02668, Poland
| | - Emilia A Lubecka
- Institute of Informatics, Faculty of Mathematics, Physics, and Informatics, University of Gdańsk, Wita Stwosza 57, Gdańsk 80-308, Poland
| | - Agnieszka G Lipska
- Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, Gdańsk 80-308, Poland
| | - Celina Sikorska
- Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, Gdańsk 80-308, Poland
| | - Sergey A Samsonov
- Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, Gdańsk 80-308, Poland
| | - Adam K Sieradzan
- Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, Gdańsk 80-308, Poland.,School of Computational Sciences, Korea Institute for Advanced Study, 85 Hoegiro, Dongdaemun-gu, Seoul 130-722, Republic of Korea
| | - Artur Giełdoń
- Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, Gdańsk 80-308, Poland
| | - Adam Liwo
- Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, Gdańsk 80-308, Poland.,School of Computational Sciences, Korea Institute for Advanced Study, 85 Hoegiro, Dongdaemun-gu, Seoul 130-722, Republic of Korea
| | - Rafał Ślusarz
- Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, Gdańsk 80-308, Poland
| | - Magdalena Ślusarz
- Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, Gdańsk 80-308, Poland
| | - Jooyoung Lee
- School of Computational Sciences, Korea Institute for Advanced Study, 85 Hoegiro, Dongdaemun-gu, Seoul 130-722, Republic of Korea
| | - Keehyoung Joo
- Center for Advanced Computation, Korea Institute for Advanced Study, 85 Hoegiro, Dongdaemun-gu, Seoul 130-722, Republic of Korea
| | - Cezary Czaplewski
- Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, Gdańsk 80-308, Poland
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7
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Abriata LA, Tamò GE, Dal Peraro M. A further leap of improvement in tertiary structure prediction in CASP13 prompts new routes for future assessments. Proteins 2019; 87:1100-1112. [PMID: 31344267 DOI: 10.1002/prot.25787] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/26/2019] [Accepted: 07/19/2019] [Indexed: 12/22/2022]
Abstract
We present our assessment of tertiary structure predictions for hard targets in Critical Assessment of Structure Prediction round 13 (CASP13). The analysis includes (a) assignment and discussion of best models through scores-aided visual inspection of models for each evaluation unit (EU); (b) ranking of predictors resulting from this evaluation and from global scores; and (c) evaluation of progress, state of the art, and current limitations of protein structure prediction. We witness a sizable improvement in tertiary structure prediction building on the progress observed from CASP11 to CASP12, with (a) top models reaching backbone RMSD <3 å for several EUs of size <150 residues, contributed by many groups; (b) at least one model that roughly captures global topology for all EUs, probably unprecedented in this track of CASP; and (c) even quite good models for full, unsplit targets. Better structure predictions are brought about mainly by improved residue-residue contact predictions, and since this CASP also by distance predictions, achieved through state-of-the-art machine learning methods which also progressed to work with slightly shallower alignments compared to CASP12. As we reach a new realm of tertiary structure prediction quality, new directions are proposed and explored for future CASPs: (a) dropping splitting into EUs, (b) rethinking difficulty metrics probably in terms of contact and distance predictions, (c) assessing also side chains for models of high backbone accuracy, and (d) assessing residue-wise and possibly residue-residue quality estimates.
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Affiliation(s)
- Luciano A Abriata
- School of Life Sciences, Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.,Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland
| | - Giorgio E Tamò
- School of Life Sciences, Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.,Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland
| | - Matteo Dal Peraro
- School of Life Sciences, Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.,Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland
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8
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Kinch LN, Kryshtafovych A, Monastyrskyy B, Grishin NV. CASP13 target classification into tertiary structure prediction categories. Proteins 2019; 87:1021-1036. [PMID: 31294862 DOI: 10.1002/prot.25775] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 06/24/2019] [Accepted: 07/06/2019] [Indexed: 12/30/2022]
Abstract
Protein target structures for the Critical Assessment of Structure Prediction round 13 (CASP13) were split into evaluation units (EUs) based on their structural domains, the domain organization of available templates, and the performance of servers on whole targets compared to split target domains. Eighty targets were split into 112 EUs. The EUs were classified into categories suitable for assessment of high accuracy modeling (or template-based modeling [TBM]) and topology (or free modeling [FM]) based on target difficulty. Assignment into assessment categories considered the following criteria: (a) the evolutionary relationship of target domains to existing fold space as defined by the Evolutionary Classification of Protein Domains (ECOD) database; (b) the clustering of target domains using eight objective sequence, structure, and performance measures; and (c) the placement of target domains in a scatter plot of target difficulty against server performance used in the previous CASP. Generally, target domains with good server predictions had close template homologs and were classified as TBM. Alternately, targets with poor server predictions represent a mixture of fast evolving homologs, structure analogs, and new folds, and were classified as FM or FM/TBM overlap.
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Affiliation(s)
- Lisa N Kinch
- Departments of Biophysics and Biochemistry, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
| | | | | | - Nick V Grishin
- Departments of Biophysics and Biochemistry, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
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9
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Wang X, Roger M, Clément R, Lecomte S, Biaso F, Abriata LA, Mansuelle P, Mazurenko I, Giudici-Orticoni MT, Lojou E, Ilbert M. Electron transfer in an acidophilic bacterium: interaction between a diheme cytochrome and a cupredoxin. Chem Sci 2018; 9:4879-4891. [PMID: 29910941 PMCID: PMC5982212 DOI: 10.1039/c8sc01615a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 04/30/2018] [Indexed: 12/15/2022] Open
Abstract
Acidithiobacillus ferrooxidans, a chemolithoautotrophic Gram-negative bacterium, has a remarkable ability to obtain energy from ferrous iron oxidation at pH 2. Several metalloproteins have been described as being involved in this respiratory chain coupling iron oxidation with oxygen reduction. However, their properties and physiological functions remain largely unknown, preventing a clear understanding of the global mechanism. In this work, we focus on two metalloproteins of this respiratory pathway, a diheme cytochrome c4 (Cyt c4) and a green copper protein (AcoP) of unknown function. We first demonstrate the formation of a complex between these two purified proteins, which allows homogeneous intermolecular electron-transfer in solution. We then mimic the physiological interaction between the two partners by replacing one at a time with electrodes displaying different chemical functionalities. From the electrochemical behavior of individual proteins, we show that, while electron transfer on AcoP requires weak electrostatic interaction, electron transfer on Cyt c4 tolerates different charge and hydrophobicity conditions, suggesting a pivotal role of this protein in the metabolic chain. The electrochemical study of the proteins incubated together demonstrates an intermolecular electron transfer involving the protein complex, in which AcoP is reduced through the high potential heme of Cyt c4. Modelling of the electrochemical signals at different scan rates allows us to estimate the rate constant of this intermolecular electron transfer in the range of a few s-1. Possible routes for electron transfer in the acidophilic bacterium are deduced.
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Affiliation(s)
- X Wang
- Aix Marseille Univ , CNRS , IMM , BIP , UMR 7281 , 31 Chemin Aiguier , 13009 Marseille , France . ;
| | - M Roger
- School of Life Sciences , University of Dundee , Dundee , DD1 5EH , Scotland , UK
| | - R Clément
- Aix Marseille Univ , CNRS , IMM , BIP , UMR 7281 , 31 Chemin Aiguier , 13009 Marseille , France . ;
| | - S Lecomte
- Institute for Chemistry and Biology of Membrane and Nano-objects , Allée Geoffroy St Hilaire , 33600 Pessac , France
| | - F Biaso
- Aix Marseille Univ , CNRS , IMM , BIP , UMR 7281 , 31 Chemin Aiguier , 13009 Marseille , France . ;
| | - L A Abriata
- Laboratory for Biomolecular Modeling , École Polytechnique Fédérale de Lausanne and Swiss Institute of Bioinformatics , AAB014, Station 19 , 1015 Lausanne , Switzerland
| | - P Mansuelle
- Aix Marseille Univ , CNRS , Institut de Microbiologie de la Méditerranée , FR 3479, Plate-forme Protéomique, Marseille Protéomique (MaP), B.P. 71 , 13402 Marseille Cedex 20 , France
| | - I Mazurenko
- School of Biomedical Sciences , Leeds , LS2 9JT , UK
| | - M T Giudici-Orticoni
- Aix Marseille Univ , CNRS , IMM , BIP , UMR 7281 , 31 Chemin Aiguier , 13009 Marseille , France . ;
| | - E Lojou
- Aix Marseille Univ , CNRS , IMM , BIP , UMR 7281 , 31 Chemin Aiguier , 13009 Marseille , France . ;
| | - M Ilbert
- Aix Marseille Univ , CNRS , IMM , BIP , UMR 7281 , 31 Chemin Aiguier , 13009 Marseille , France . ;
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10
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Moult J, Fidelis K, Kryshtafovych A, Schwede T, Tramontano A. Critical assessment of methods of protein structure prediction (CASP)-Round XII. Proteins 2018; 86 Suppl 1:7-15. [PMID: 29082672 PMCID: PMC5897042 DOI: 10.1002/prot.25415] [Citation(s) in RCA: 245] [Impact Index Per Article: 40.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 10/25/2017] [Accepted: 10/27/2017] [Indexed: 12/24/2022]
Abstract
This article reports the outcome of the 12th round of Critical Assessment of Structure Prediction (CASP12), held in 2016. CASP is a community experiment to determine the state of the art in modeling protein structure from amino acid sequence. Participants are provided sequence information and in turn provide protein structure models and related information. Analysis of the submitted structures by independent assessors provides a comprehensive picture of the capabilities of current methods, and allows progress to be identified. This was again an exciting round of CASP, with significant advances in 4 areas: (i) The use of new methods for predicting three-dimensional contacts led to a two-fold improvement in contact accuracy. (ii) As a consequence, model accuracy for proteins where no template was available improved dramatically. (iii) Models based on a structural template showed overall improvement in accuracy. (iv) Methods for estimating the accuracy of a model continued to improve. CASP continued to develop new areas: (i) Assessing methods for building quaternary structure models, including an expansion of the collaboration between CASP and CAPRI. (ii) Modeling with the aid of experimental data was extended to include SAXS data, as well as again using chemical cross-linking information. (iii) A team of assessors evaluated the suitability of models for a range of applications, including mutation interpretation, analysis of ligand binding properties, and identification of interfaces. This article describes the experiment and summarizes the results. The rest of this special issue of PROTEINS contains papers describing CASP12 results and assessments in more detail.
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Affiliation(s)
- John Moult
- Institute for Bioscience and Biotechnology Research and Department of Cell Biology and Molecular Genetics, University of Maryland, 9600 Gudelsky Drive, Rockville, MD 20850, USA
| | - Krzysztof Fidelis
- Genome Center, University of California, Davis, 451 Health Sciences Drive, Davis, CA 95616, USA
| | - Andriy Kryshtafovych
- Genome Center, University of California, Davis, 451 Health Sciences Drive, Davis, CA 95616, USA
| | - Torsten Schwede
- University of Basel, Biozentrum & SIB Swiss Institute of Bioinformatics, Basel, Switzerland
| | - Anna Tramontano
- Department of Physics and Istituto Pasteur - Fondazione Cenci Bolognetti, Sapienza University of Rome, P.le Aldo Moro, 5, 00185 Rome, Italy
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11
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Haas J, Barbato A, Behringer D, Studer G, Roth S, Bertoni M, Mostaguir K, Gumienny R, Schwede T. Continuous Automated Model EvaluatiOn (CAMEO) complementing the critical assessment of structure prediction in CASP12. Proteins 2017; 86 Suppl 1:387-398. [PMID: 29178137 DOI: 10.1002/prot.25431] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 11/10/2017] [Accepted: 11/22/2017] [Indexed: 12/22/2022]
Abstract
Every second year, the community experiment "Critical Assessment of Techniques for Structure Prediction" (CASP) is conducting an independent blind assessment of structure prediction methods, providing a framework for comparing the performance of different approaches and discussing the latest developments in the field. Yet, developers of automated computational modeling methods clearly benefit from more frequent evaluations based on larger sets of data. The "Continuous Automated Model EvaluatiOn (CAMEO)" platform complements the CASP experiment by conducting fully automated blind prediction assessments based on the weekly pre-release of sequences of those structures, which are going to be published in the next release of the PDB Protein Data Bank. CAMEO publishes weekly benchmarking results based on models collected during a 4-day prediction window, on average assessing ca. 100 targets during a time frame of 5 weeks. CAMEO benchmarking data is generated consistently for all participating methods at the same point in time, enabling developers to benchmark and cross-validate their method's performance, and directly refer to the benchmarking results in publications. In order to facilitate server development and promote shorter release cycles, CAMEO sends weekly email with submission statistics and low performance warnings. Many participants of CASP have successfully employed CAMEO when preparing their methods for upcoming community experiments. CAMEO offers a variety of scores to allow benchmarking diverse aspects of structure prediction methods. By introducing new scoring schemes, CAMEO facilitates new development in areas of active research, for example, modeling quaternary structure, complexes, or ligand binding sites.
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Affiliation(s)
- Jürgen Haas
- Biozentrum, University of Basel, Switzerland.,SIB Swiss Institute of Bioinformatics, Computational Structural Biology, Basel, Switzerland
| | - Alessandro Barbato
- Biozentrum, University of Basel, Switzerland.,SIB Swiss Institute of Bioinformatics, Computational Structural Biology, Basel, Switzerland
| | - Dario Behringer
- Biozentrum, University of Basel, Switzerland.,SIB Swiss Institute of Bioinformatics, Computational Structural Biology, Basel, Switzerland
| | - Gabriel Studer
- Biozentrum, University of Basel, Switzerland.,SIB Swiss Institute of Bioinformatics, Computational Structural Biology, Basel, Switzerland
| | - Steven Roth
- Biozentrum, University of Basel, Switzerland.,SIB Swiss Institute of Bioinformatics, Computational Structural Biology, Basel, Switzerland
| | - Martino Bertoni
- Biozentrum, University of Basel, Switzerland.,SIB Swiss Institute of Bioinformatics, Computational Structural Biology, Basel, Switzerland
| | - Khaled Mostaguir
- Biozentrum, University of Basel, Switzerland.,SIB Swiss Institute of Bioinformatics, Computational Structural Biology, Basel, Switzerland
| | - Rafal Gumienny
- Biozentrum, University of Basel, Switzerland.,SIB Swiss Institute of Bioinformatics, Computational Structural Biology, Basel, Switzerland
| | - Torsten Schwede
- Biozentrum, University of Basel, Switzerland.,SIB Swiss Institute of Bioinformatics, Computational Structural Biology, Basel, Switzerland
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