EVOLUTION OF DISINTEGRIN CYSTEINE-RICH AND MAMMALIAN MATRIX-DEGRADINGMETALLOPROTEINASES - GENE DUPLICATION AND DIVERGENCE OF A COMMON ANCESTOR RATHER THAN CONVERGENT EVOLUTION

The evolution of the Metalloproteinase Disintegrin Cysteine-rich (MDC) gene family and that of the mammalian Matrix-degrading Metalloprotein ases (MMPs) are compared. The alignment of snake venom and mammalian M DC and MMP precursor sequences generated a phylogenetic tree that grou ped these proteins mainly according to their function. Based on this o bservation, a common ancestry is suggested for mammalian and snake ven om MDCs; it is also possible that gene duplication of the already-asse mbled domain structure, followed by divergence of the copies, may have significantly contributed to the evolution of the functionally divers e MDC proteins. The data also suggest that the structural resemblance of the zinc-binding motif of venom MDCs and MMPs may best be explained by common ancestry and conservation of the proteolytic motifs during the divergence of the proteins rather than through convergent evolutio n.