4K3B:
reference: Structural insight into the biogenesis of beta-barrel membrane proteins., Noinaj N, Kuszak AJ, Gumbart JC, Lukacik P, Chang H, Easley NC, Lithgow T, Buchanan SK, Nature. 2013 Sep 1. doi: 10.1038/nature12521. PMID: 23995689

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