Protein Structure Initiative

The Protein Structure Initiative (PSI) was a USA based project that aimed at accelerating discovery in structural genomics and contribute to understanding biological function.^[1] Funded by the U.S. National Institute of General Medical Sciences (NIGMS) between 2000 and 2015, its aim was to reduce the cost and time required to determine three-dimensional protein structures and to develop techniques for solving challenging problems in structural biology, including membrane proteins. Over a dozen research centers have been supported by the PSI for work in building and maintaining high-throughput structural genomics pipelines, developing computational protein structure prediction methods, organizing and disseminating information generated by the PSI, and applying high-throughput structure determination to study a broad range of important biological and biomedical problems.

The project has been organized into three separate phases. The first phase of the Protein Structure Initiative (PSI-1) spanned from 2000 to 2005, and was dedicated to demonstrating the feasibility of high-throughput structure determination, solving unique protein structures, and preparing for a subsequent production phase.^[2] The second phase, PSI-2, focused on implementing the high-throughput structure determination methods developed in PSI-1, as well as homology modeling and addressing bottlenecks like modeling membrane proteins.^[3] The third phase, PSI:Biology, began in 2010 and consisted of networks of investigators applying high-throughput structure determination to study a broad range of biological and biomedical problems.^[4] PSI program ended on 7/1/2015,^[5] even that some of the PSI centers continue structure determination supported by other funding mechanisms.