5HUQ:
reference: METALLOPROTEINS. A tethered niacin-derived pincer complex with a nickel-carbon bond in lactate racemase., Desguin B, Zhang T, Soumillion P, Hols P, Hu J, Hausinger RP, Science. 2015 Jul 3;349(6243):66-9. doi: 10.1126/science.aab2272. PMID: 26138974

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