This domain is found in Flagellar hook protein FlgE from Campylobacter jejuni and similar proteins found in Epsilonproteobacteria. Around 100 copies of FlgE polymerise to form a tubular helical structure: the bacterial flagellar hook. This protein is organised into five domains. This entry represents domain D3, which is made of two discontinuous segments. It shows a set of eight beta-strands separated into two groups by two alpha-helices that form an alpha-beta barrel. This domain is not conserved in other bacterial FlgE proteins [1,2].

1: Structural insights into bacterial flagellar hooks similarities and specificities. Yoon YH, Barker CS, Bulieris PV, Matsunami H, Samatey FA; Sci Rep. 2016;6:35552. PMID:27759043

2: Complete structure of the bacterial flagellar hook reveals extensive set of stabilizing interactions. Matsunami H, Barker CS, Yoon YH, Wolf M, Samatey FA; Nat Commun. 2016;7:13425. PMID:27811912