3GFB:
reference: Structure and function of the l-threonine dehydrogenase (TkTDH) from the hyperthermophilic archaeon Thermococcus kodakaraensis., Bowyer A, Mikolajek H, Stuart JW, Wood SP, Jamil F, Rashid N, Akhtar M, Cooper JB, J Struct Biol. 2009 Nov;168(2):294-304. Epub 2009 Jul 16. PMID: 19616102

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