RESIDUE 6CS 21 CONECT O 1 C CONECT C 3 O OXT CA CONECT OXT 2 C HXT CONECT CA 4 C N CB HA CONECT N 2 CA CAI CONECT CAI 3 N CAA NAG CONECT CAA 4 CAI HAA1 HAA2 HAA3 CONECT NAG 3 CAI CG2 HN CONECT CG2 4 NAG CB HG21 HG22 CONECT CB 4 CA CG2 OG1 HB CONECT OG1 2 CB HOG1 CONECT HXT 1 OXT CONECT HA 1 CA CONECT HN 1 NAG CONECT HAA1 1 CAA CONECT HAA2 1 CAA CONECT HAA3 1 CAA CONECT HG21 1 CG2 CONECT HG22 1 CG2 CONECT HB 1 CB CONECT HOG1 1 OG1 END HET 6CS 21 HETNAM 6CS (4S,5S)-5-HYDROXY-2-METHYL-1,4,5,6-TETRAHYDROPYRIMIDINE HETNAM 2 6CS -4-CARBOXYLIC ACID FORMUL 6CS C6 H10 N2 O3