PRENRL_3D: a computer program for an automatic creation of NRL_3D, protein sequence-structure database, from the Protein Data Bank.

Recently, we have developed a sequence-structure database of protein information, NRL_3D, that is extracted from the Protein Data Bank (PDB) of the Brookhaven National Laboratory. NRL_3D provides a vehicle for the retrieval of the three-dimensional coordinates of protein fragments as identified by sequence properties. These data are formulated to allow access by standard sequence analysis programs such as those provided by the Protein Identification Resource (PIR). Because the PDB is updated four times per year, semimanual construction of NRL_3D in coordination with these updates becomes a time-consuming and inefficient task. Hence, we have developed a computer program (PRENRL_3D) in the "C" computer language that automatically extracts NRL_3D from the PDB. Although the program was developed in a VAX/VMS environment, care was taken to ensure its portability to other computer systems. Customized versions of the NRL_3D database can be created from the PDB entry files using various options available in PRENRL_3D, such as selection of entries determined at high resolution and with low R-value. The program has been developed modularly and it contains a number of generalized procedures for manipulating various information in the PDB.