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Rangan P, Masquida B, Westhof E, Woodson SA.Rangan P, et al.Proc Natl Acad Sci U S A. 2003 Feb 18;100(4):1574-9. doi: 10.1073/pnas.0337743100. Epub 2003 Feb 6.Proc Natl Acad Sci U S A. 2003.PMID: 12574513Free PMC article.