BMP-1: Resurrection As Procollagen C-Proteinase

The characterization of the function of bone morphogenetic protein-1 (BMP-1) was reported in last week's issue of Science (19 January, p. 360) . In his Perspective, A. H. Reddi explains why it was surprising (and important) that BMP-1 turned out to be identical to procollagen C-proteinase, the enzyme responsible for triggering the self-assembly of collagen.