Purification, characterization and preliminary crystallographic studies of a PR-10 protein from Pachyrrhizus erosus seeds

A 16 kDa protein SPE16 was purified from the seeds of Pachyrrhizus erosus. Its N-terminal amino-acid sequence showed significant sequence homology to pathogenesis-related proteins from the PR-­10 family. An activity assay indicated that SPE16 possesses ribonuclease activity as do some other PR-10 proteins. SPE16 crystals were obtained by the hanging-drop vapour-diffusion method. The space group is P2₁2₁2₁, with unit-cell parameters a = 53.36, b = 63.70, c = 72.96 Å.