1PSS:
reference: Crystallographic analyses of site-directed mutants of the photosynthetic reaction center from Rhodobacter sphaeroides., Chirino AJ, Lous EJ, Huber M, Allen JP, Schenck CC, Paddock ML, Feher G, Rees DC, Biochemistry 1994 Apr 19;33(15):4584-93. PMID: 8161514

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