TEXTAL™: Automated Crystallographic Protein Structure Determination

This paper reports on TEXTALTM, a deployed application that uses a variety of AI techniques to automate the process of determining the 3D structure of proteins by x-ray crystallography. The TEXTALTM project was initiated in 1998, and the application is currently deployed in three ways: (1) a web-based interface called WebTex, operational since June 2002; (2) as the automated modelbuilding component of an integrated crystallography software called PHENIX, first released in July 2003; (3) binary distributions, available since September 2004. TEXTALTM and its sub-components are currently being used by crystallographers around the world, both in the industry and in academia. TEXTALTM saves up to weeks of effort typically required to determine the structure of one protein; the system has proven to be particularly helpful when the quality of the data is poor, which is very often the case. Automated protein modeling systems like TEXTALTM are critical to the structural genomics initiative, a worldwide effort to determine the 3D structure of all proteins in a high-throughput mode, thereby keeping up with the rapid growth of genomic sequence databases.