4UB8:
reference: Native structure of photosystem II at 1.95 A resolution viewed by femtosecond X-ray pulses., Suga M, Akita F, Hirata K, Ueno G, Murakami H, Nakajima Y, Shimizu T, Yamashita K, Yamamoto M, Ago H, Shen JR, Nature. 2015 Jan 1;517(7532):99-103. doi: 10.1038/nature13991. Epub 2014 Nov 26. PMID: 25470056

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