This domain has a cyclophilin-like fold, consisting of an eight-stranded beta-barrel with an alpha helix located between the beta-2 and beta-3 strands and a 310 helix located between the beta-7 and beta-8 strands. The catalytic site found in human cyclophilin is not conserved in this domain, suggesting a different function for this domain [1,2].

1: Crystal structure of TM1367 from Thermotoga maritima at 1.90 A resolution reveals an atypical member of the cyclophilin (peptidylprolyl isomerase) fold. Jin KK, Krishna SS, Schwarzenbacher R, McMullan D, Abdubek P, Agarwalla S, Ambing E, Axelrod H, Canaves JM, Chiu HJ, Deacon AM, DiDonato M, Elsliger MA, Feuerhelm J, Godzik A, Grittini C, Grzechnik SK, Hale J, Hampton E, Haugen J, Hornsby M, Jaroszewski L, Klock HE, Knuth MW, Koesema E, Kreusch A, Kuhn P, Lesley SA, Miller MD, Moy K, Nigoghossian E, Okach L, Oommachen S, Paulsen J, Quijano K, Reyes R, Rife C, Stevens RC, Spraggon G, van den Bedem H, Velasquez J, White A, Wolf G, Han GW, Xu Q, Hodgson KO, Wooley J, Wilson IA; Proteins. 2006;63:1112-1118. PMID:16544291

2: Hypothetical protein AF2241 from Archaeoglobus fulgidus adopts a cyclophilin-like fold. Ai X, Li L, Semesi A, Yee A, Arrowsmith CH, Li SS, Choy WY; J Biomol NMR. 2007;38:353-358. PMID:17610131