6AHW:
reference: Untying a Protein Knot by Circular Permutation., Chuang YC, Hu IC, Lyu PC, Hsu SD, J Mol Biol. 2019 Jan 9. pii: S0022-2836(19)30007-5. doi:, 10.1016/j.jmb.2019.01.005. PMID: 30639189

This OCA Structure page
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