2X9X:
reference: Supramolecular organization of the repetitive backbone unit of the Streptococcus pneumoniae pilus., Spraggon G, Koesema E, Scarselli M, Malito E, Biagini M, Norais N, Emolo C, Barocchi MA, Giusti F, Hilleringmann M, Rappuoli R, Lesley S, Covacci A, Masignani V, Ferlenghi I, PLoS One. 2010 Jun 15;5(6):e10919. PMID: 20559564

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