Members of this family of nucleic acid binding domains are predominantly found in elongation factor P, where they adopt an OB-fold, with five beta-strands forming a beta-barrel in a Greek-key topology [1].

1: Crystal structure of elongation factor P from Thermus thermophilus HB8. Hanawa-Suetsugu K, Sekine S, Sakai H, Hori-Takemoto C, Terada T, Unzai S, Tame JR, Kuramitsu S, Shirouzu M, Yokoyama S; Proc Natl Acad Sci U S A. 2004;101:9595-9600. PMID:15210970