This domain of unknown function is found at the C-terminal of Protein NO VEIN from Arabidopsis, a protein essential for cell fate determination during embryogenesis [2]. It mediates this process through an auxin-dependent pathway [3]. This domain is also found in some restriction endonucleases.

1: Sequence, structure and functional diversity of PD-(D/E)XK phosphodiesterase superfamily. Steczkiewicz K, Muszewska A, Knizewski L, Rychlewski L, Ginalski K; Nucleic Acids Res. 2012;40:7016-7045. PMID:22638584

2: Identification of genes required for embryo development in Arabidopsis. Tzafrir I, Pena-Muralla R, Dickerman A, Berg M, Rogers R, Hutchens S, Sweeney TC, McElver J, Aux G, Patton D, Meinke D; Plant Physiol. 2004;135:1206-1220. PMID:15266054

3: NO VEIN facilitates auxin-mediated development in Arabidopsis. Tsugeki R, Ditengou FA, Palme K, Okada K; Plant Signal Behav. 2010;5:1249-1251. PMID:20729639