Spermadhesins, 12,000-14,000 M-r mammalian proteins, include lectins i
nvolved in sperm-egg binding and display a single CUB domain architect
ure. We report the crystal structures of porcine seminal plasma PSP-I/
PSP-II, a heterodimer of two glycosylated spermadhesins. and bovine aS
FP at 2.4 Angstrom and 1.9 Angstrom resolution respectively.