To create the cyclic peptide, we delete Ser 301, Gly 302, Val 303, Thr 304 (except for the carbonyl group), Lys 310, and the carbonyl group of Phe 309, as these fragments are not needed in the cyclic peptide (Figure ). We then add a methylene (CH2) group at the para position of Phe 309 by building a tetrahedral methyl group (CH3) in UCSF Chimera and then deleting one of the hydrogen atoms of the methyl group (Figure ).