Peptidyl-prolyl cis-trans isomerase CYP38 from Arabidopsis is required for the assembly and stabilization of PSII [1]. It consists of an N-terminal helical bundle and a C-terminal cyclophilin beta-barrel (Pfam:PF00160)[1]. This entry represents the N-terminal helical bundle found in Cyp37/38 from Arabidopsis and similar proteins from cyanobacteria. This domain establishes strong interactions with the C-terminal domain to avoid the access of the cyclophilin domain to other proteins [1].

1: Crystal structure of Arabidopsis cyclophilin38 reveals a previously uncharacterized immunophilin fold and a possible autoinhibitory mechanism. Vasudevan D, Fu A, Luan S, Swaminathan K; Plant Cell. 2012;24:2666-2674. PMID:22706283