This domain is found in Basophilic leukemia-expressed protein Bles03 from humans (also known as UPF0696 protein C11orf68, Swiss:Q9H3H3) and various proteins from eukaryotes, bacteria and archaea. Bles03 has been suggested to have phosphothreonine lyase activity and to play a role in the biosynthesis of dehydro amino acids [1]. It shows a two-layer sandwich architecture with a a nine-stranded beta-sheet and three alpha-helices on each side [2].

1: The structure at 2.5 A resolution of human basophilic leukemia-expressed protein BLES03. Bitto E, Bingman CA, Robinson H, Allard ST, Wesenberg GE, Phillips GN Jr; Acta Crystallogr Sect F Struct Biol Cryst Commun. 2005;61:812-817. PMID:16511166

2: Genome-wide search for eliminylating domains reveals novel function for BLES03-like proteins. Khater S, Mohanty D; Genome Biol Evol. 2014;6:2017-2033. PMID:25062915