6IVE:
reference: Molecular structure of thermostable and zinc-ion-binding gamma-class carbonic anhydrases., Wang W, Zhang Y, Wang L, Jing Q, Wang X, Xi X, Zhao X, Wang H, Biometals. 2019 Apr;32(2):317-328. doi: 10.1007/s10534-019-00190-8. Epub 2019 Mar, 20. PMID: 30895492

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