4YAH:
reference: The contribution of methionine to the stability of the Escherichia coli MetNIQ ABC transporter-substrate binding protein complex., Nguyen PT, Li QW, Kadaba NS, Lai JY, Yang JG, Rees DC, Biol Chem. 2015 Mar 24. pii:, /j/bchm.just-accepted/hsz-2015-0131/hsz-2015-0131.xml. doi:, 10.1515/hsz-2015-0131. PMID: 25803078

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