OEP37 is a ß barrel outer membrane protein found in chloroplasts. There is a nanomolar affinity between OEP37 channel and the precursor of Tic32, which is imported into the inner chloroplastic membrane through an obscure pathway. Additionally, it might form a novel peptide-sensitive ion channel in the outer membrane of chloroplasts throughout embryogenesis and germination. Predictions show that it features twelve ß sheets and large intermembrane loops. According to PRED-TMBB2, OEP37 forms 16 ß strands.