<p>The rudiment single hybrid motif has a beta-barrel sandwich hybrid motif, consisting of a sandwich of half-barrel shaped beta-sheets. This motif is found in the small domain of cytochrome f [<cite idref="PUB00014227"/>], as well as in the C-terminal domain of the biotin carboxylase subunit of acetyl-CoA carboxylase [<cite idref="PUB00014226"/>], and its family members, such as glycinamide ribonucleotide synthetase C-terminal domain [<cite idref="PUB00014228"/>], N5-carboxyaminoimidazole ribonucleotide synthetase PurK C-terminal domain [<cite idref="PUB00007904"/>], and glycinamide ribonucleotide transformylase PurT C-terminal domain [<cite idref="PUB00014229"/>].</p>