C_beta = Atom('CH2')
C_delta = Atom('CH2')
C_gamma = Atom('CH2')
bonds = [Bond(C_gamma, C_delta), Bond(C_beta, C_gamma), ]
pdbmap = [('PRO', {'CD': C_delta, 'CB': C_beta, 'CG': C_gamma, }, ), ]
amber_atom_type = {C_beta: 'CT', C_gamma: 'CT', C_delta: 'CT', }
name = 'pro_sidechain'
