We here report computational analyses of six outer membrane proteins of known 3D structures with respect to (1) secondary structure, (2) hydropathy, and (3) amphipathicity. Using these characteristics, as well as the presence of an N-terminal targeting sequence, a program was developed allowing prediction of integral membrane beta-barrel proteins encoded within any completely sequenced prokaryotic genome. This program, termed the beta-barrel finder (BBF) program, was used to analyze the proteins encoded within the Escherichia coli genome.