The Structural Biology Unit at St Vincent's Institute of Medical Research in Melbourne was established in 1997 following the Wellcome Trust-supported appointment of Bostjan Kobe as head. The focus of the Laboratory is studies of macromolecular interactions, using an integrated approach that employs a combination of methods such as protein chemistry, molecular biology, biosensor and computational approaches, in addition to macromolecular crystallography. The biological areas currently under study include regulation of protein function (protein kinases, phenylalanine hydroxylase), viral infection, cellular transport processes and protein domains specialised in protein-protein interactions. The recent research highlights include the determination of crystal structures of the auto-regulated proteins phenylalanine hydroxylase (Nature Struct. Biol. (1999) 6, 442-448) and importin alpha (Nature Struct. Biol. (1999) 6,338-397) and the HTLV-1 virus envelope glycoprotein gp21 as a chimera with maltose binding protein (Proc. Natl. Acad. Sci. (1999) USA 96, 4319-4324). The Unit was fortunate that a large portion of the computational and X-ray equipment presently in use has been set up mainly through the efforts of Michael Parker and Bruce Kemp prior to its establishment. The X-ray and some computational facilities are shared between the Structural Biology Unit and the Ian Potter Foundation Protein Crystallography Unit headed by Professor Parker.