Centers

Four large-scale centers, all established during the PSI pilot phase, have constructed structural genomics pipelines for the production and structural determination of proteins in a high-throughput operation. Over the 5-year period of PSI-2, these centers are expected to coordinate their efforts to generate more than 4,000 structures of protein families, and thus meet the program’s goals of increasing structural coverage of sequenced genes and providing benefits for the entire biomedical community. The centers will also develop new technologies to improve the pipeline and to increase success rates and lower costs. Each center also has an individual structural genomics research project, as described below.

 

 

During the PSI pilot phase, the JCSG developed a scalable, high-throughput structural genomics pipeline. The design of the JCSG pipeline was based on the development and integration of automated approaches for every experimental and computational step in the structural genomics process. During PSI-2, the JCSG will contribute to the overall goal of maximizing structural coverage of protein families with no structural representation and will continue development and dissemination of innovative new technologies for structural biology. The consortium will determine structures of a large number of high-value targets, including structurally challenging proteins, such as membrane proteins and protein complexes. The JCSG consortium theme will be the “central machinery of life” — proteins that are conserved in all kingdoms of life.

Principal investigator: Ian Wilson, Scripps Research Institute

Participating institutions: The Scripps Research Institute, the University of California at San Diego, the Burnham Institute, Stanford Synchrotron Radiation Laboratory, and the Genomics Institute of the Novartis Research Foundation

Web site: http://www.jcsg.org

 

 

During the PSI pilot phase, this center automated synchrotron-based protein structure determination and solved many unique structures. In PSI-2, the multi-institutional consortium will rapidly determine the structures of large numbers of strategically selected proteins using x-ray crystallography both to provide structural coverage of major protein superfamilies and to elucidate the entire protein folding space. Targets include proteins from pathogens and higher organisms. The efficient structure determination pipeline will include the classification of genomic sequences, cloning and expression of genes and gene fragments, purification and crystallization of proteins, analysis of structures for folds and functions, and homology modeling of related structures.

Principal investigator: Andrzej Joachimiak, Argonne National Laboratory

Participating institutions: Argonne National Laboratory, European Bioinformatics Institute, University College London, and the University of Toronto

Web site: http://www.mcsg.anl.gov

 

 

During the pilot phase, this academic consortium determined more than 200 structures of both prokaryotic and eukaryotic proteins, including human proteins, using X-ray crystallography and solution-state NMR spectroscopy. It also developed several new technologies for eukaryotic protein production and protein structure analysis. In PSI-2, the consortium plans to solve both prokaryotic and eukaryotic structural representatives from the major domain families constituting the eukaryotic proteome. Its biological-focus project targets networks of co-functioning proteins (BioNets) involved in developmental biology and cancer.
Principal investigator: Gaetano Montelione, Rutgers University
Participating institutions: Columbia University, Hauptman Woodward Medical Research Institute, Ontario Cancer Institute at the University of Toronto, Pacific Northwest National Laboratories, Rutgers University, Robert Wood Johnson Medical School at the UMDNJ, Weill Medical School at Cornell University, and Yale University

Web site: http://www.nesg.org

 

 

This collaborative group of industry, academic, and government labs participated in the PSI pilot phase. They have developed a fully-integrated, high-throughput center for all the components of structural genomics, including an industrial protein production robotic pipeline. In parallel to automated protein production in bacterial cells, the center uses production in insect cells for problematic eukaryotic proteins. During PSI-2, the consortium’s individual project focuses on new targets, principally protein phosphatases and multidomain eukaryotic proteins.

Principal investigator: Stephen K. Burley, Structural GenomiX, Inc., San Diego, Calif.

Participating institutions: Structural GenomiX, Inc.; Albert Einstein College of Medicine; Brookhaven National Laboratory; Case Western Reserve University; Columbia University; University of California, San Francisco

Web site: http://www.nysgrc.org/

Six specialized centers will develop innovative methods, approaches, and technologies for producing and determining the structures of proteins that traditionally have been difficult to study. These include small protein complexes, membrane proteins, and proteins from higher organisms, including humans During the next 5 years, these efforts are expected to overcome bottlenecks in the structural genomics pipeline and approach high-throughput operation. The specialized centers are also expected to determine a significant number of these challenging protein structures.

 

This center is focused on the development, operation, and deployment of novel approaches in miniaturization, integration, and automation with an aim toward lowering the overall cost of gene to structure for all researchers. Primary initiatives include whole gene synthesis for the production of optimized protein constructs and parallel protein purification with integrated small-scale biophysical characterization, micro-capillary based crystallization technologies, and the use of a mini-synchrotron. The initial target application area is oncology.

Principal investigator: Lance J. Stewart, deCODE Biostructures

Participating institutions: deCODE Biostructures; The Scripps Research Institute; University of Chicago; Lyncean Technologies, Inc.; and Micronics, Inc.

Web site: http://www.atcg3d.org

 

 

During the PSI pilot phase, this center focused on structures from eukaryotic genomes, initially from the plant Arabidopsis thaliana and subsequently from human, mouse, zebra fish, and others. As a specialized center, the focus will continue to be on the determination of eukaryotic protein structures, especially human proteins related to disease or cell differentiation and proteins from families represented only in eukaryotes. The center uses two forms of protein production: expression of targets in E. coli and automated cell-free production using wheat germ extracts. The group uses X-ray crystallography and solution-state NMR spectroscopy to solve structures.   

Principal investigator: John L. Markley, University of Wisconsin, Madison
Participating institutions: University of Wisconsin, Madison; Medical College of Wisconsin

Web site: http://www.uwstructuralgenomics.org

 

 

The center plans to refine several steps in the structure determination pipeline, from sample preparation to the collection of crystal diffraction data. The researchers’ efforts will center on protein expression, purification, and the crystallization of small protein complexes and transmembrane proteins (all from yeast). Researchers will make and purify antibodies that target transmembrane proteins and crystallize the protein-antibody complexes. They will work on cryopreservation of protein crystals and plan to improve automation and analysis of crystallization screening results.

Principal investigator: George T. De Titta, Hauptman-Woodward Medical Research Institute

Participating institutions: Hauptman-Woodward Medical Research Institute,

University of Rochester, Cornell University, Stanford Synchrotron Light

Source, University of Pittsburgh, University of Washington at Seattle, and the University of Toronto

Web site: http://www.chtsb.org

 

 

This specialized center will concentrate on determining structures of membrane proteins derived from archaea, bacteria, and humans. Genes are selected using bioinformatics to optimize coverage of classes of membrane proteins. Investigators will use four expression systems, including MISTIC (Membrane-Integrating Sequence for Translation of Integral membrane protein Constructs) systems, which allow expression of eukaryotic proteins in E. coli and subsequent targeting of the proteins to the bacterial membrane. Structures will be determined by detergent-based crystallization followed by X-ray structure determination at the Advanced light source (ALS), 2-D crystallization in lipid bilayers, single particle electron imaging, and NMR. Protein function is assayed.

Principal investigator: Robert M. Stroud, University of California, San Francisco

Participating institutions: University of California, San Francisco;

The Salk Institute; Advanced Light Source (ALS) Lawrence Berkeley National Laboratory; University of California, Los Angeles; University of California, Davis

Web site: http://csmp.ucsf.edu

 

 

The investigators will address problems related to the key steps of the production of soluble proteins and crystallization. Emphasis will be on protein solubility and crystallization of small protein complexes, soluble domains of membrane proteins, and eukaryotic proteins. This center will develop chaperone-assisted crystallography and engineer proteins for crystallization by mutating their surfaces and adding fusion proteins.

Principal investigator: Thomas C. Terwilliger, Los Alamos National Laboratory

Participating institutions: Los Alamos National Laboratory; University of Chicago; University of Virginia; University of California, Los Angeles; Lawrence Livermore National Laboratory; Lawrence Berkeley National Laboratory

Web site: http://techcenter.mbi.ucla.edu/

 

The center’s goal is to speed structure determination for membrane proteins, starting with bioinformatics analysis of sequence. The investigators will also address bottlenecks in the expression, purification, and structure determination of membrane proteins. The center uses automated cloning and expression, high-throughput expression screening, detergents to help solubilize folded proteins, and large-scale purification and labeling of proteins for NMR and X-ray crystallography.  Proteins will be expressed in insect and mammalian cells as well as E. coli.

Principal investigator: Wayne A. Hendrickson, New York Structural Biology Center

Participating institutions: Columbia University, Albert Einstein College of Medicine, New York University, The Rockefeller University, SUNY Buffalo, University of Medicine and Dentistry of New Jersey, and Yale University

Web site:  http://www.nycomps.org

Two homology modeling centers will develop innovative computational methods for reliably predicting the three-dimensional structures of proteins, bringing the PSI closer to its long-range goal of making it easy to determine the shapes of proteins from genetic sequence information. The centers will use PSI structures solved experimentally to help develop computational methods and verify model accuracy.

 

Joint Center for Molecular Modeling
Collaborating scientists will use mathematical tools to build software programs that can accurately predict the structures of proteins distantly related to ones with known structures. They also will develop novel ways to extract rules and trends of how structures change and evolve, enabling protein structure prediction from sequence. Future applications could include predicting, for example, how a human protein differs from its counterpart in mice or bacteria. The modeling tools will be made available to researchers worldwide through open-source databases.
Principal investigator: Adam Godzik, Burnham Institute for Medical Research
Participating institutions: University of California, San Diego
Web site: Forthcoming

 

 

New Methods for High-Resolution Comparative Modeling
This center brings together a team of investigators in biophysics, mathematics, statistics, and computer science to improve the modeling accuracy of proteins both closely and distantly related to proteins with known structures. The team will develop modeling methods for a wide range of proteins, including cancer proteins and ones that could serve as drug targets for new cancer treatments. To explore how modeling can enhance experimental structure determination, the center will model some structures for molecular replacement as they’re being solved by the PSI research centers. 
Principal investigator: Roland Dunbrack, Fox Chase Cancer Center
Participating institutions: University of Washington, Washington University in St. Louis, and the University of California, Berkeley
Web site: Forthcoming

Two centers are being established to centralize resources developed by the PSI centers and increase the scientific community’s access to them.

 

PSI Materials Repository
The Harvard Institute of Proteomics, part of the Harvard Medical School, has operated the PSI-Materials Repository since September 2006. This facility is working to collect, sequence, annotate, and store the more than 50,000 plasmid clones generated by the PSI research centers. A limited number of clones are now available for searching and ordering at http://plasmid.hms.harvard.edu. The facility is continuously adding more clones.
Principal Investigator: Joshua LaBaer, Harvard Institute of Proteomics
Web site: http://www.hip.harvard.edu/PSIMR/index.htm

 

 

PSI Structural Genomics Knowledgebase
Launched in February 2008, the PSI Structural Genomics Knowledgebase makes all the products generated by the PSI centers available to the greater scientific community. This Web portal enables scientists to search for the best available information on protein structures, their biological function, and their experimental determination. The PSI SGKB merges these features with external resources, making it possible for researchers to access a wealth of information from one site.
Web site: http://kb.psi-structuralgenomics.org/KB/