ARO 9 1 1 HN N -C CA 1 5 HA CA N C CB 2 6 HB CB CA CG 1 5 HG CG CB CD OH 2 6 HD CD CG NE 1 2 HH OH CG CB 1 1 HE NE CD CZ 2 3 HH1 NH1 CZ NE 2 3 HH2 NH2 CZ NH1