6QMM:
reference: Crystal structure of dimeric Synechococcus Spermidine Synthase with bound polyamine substrate and product., Guedez G, Pothipongsa A, Siren S, Liljeblad A, Jantaro S, Incharoensakdi A, Salminen TA, Biochem J. 2019 Mar 15. pii: BCJ20180811. doi: 10.1042/BCJ20180811. PMID: 30877192

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