SARS protein sequences were compared by BLAST/PSI-BLAST to sequences for which 3D structure is known. SARS proteins for which related 3D-structures were found are listed below. The links present sequence alignments and mapping onto the related 3D structure using the Cn3D molecular graphics viewer. Additional related structures were selected from the VAST 3D-structure neighbors of the proteins identified by BLAST/PSI-BLAST.