This domain is found in elongation factor 3A where it packs against the bottom of the concave face of the HEAT domain [1].

1: Structure of eEF3 and the mechanism of transfer RNA release from the E-site. Andersen CB, Becker T, Blau M, Anand M, Halic M, Balar B, Mielke T, Boesen T, Pedersen JS, Spahn CM, Kinzy TG, Andersen GR, Beckmann R; Nature. 2006;443:663-668. PMID:16929303