{"rfam": {"acc": "RF00162", "id": "SAM", "description": "SAM riboswitch aptamer (S box leader)", "comment": "The SAM riboswitch is found upstream of a number of genes which code for proteins involved in methionine or cysteine biosynthesis in Gram-positive bacteria. The SAM riboswitch acts at the level of transcription termination control. The predicted structure consists of a complex stem-loop region followed by a single stem loop terminator region. An alternative and mutually exclusive form involves bases in the 3' segment of helix 1 with those in the 5' region of helix 5 to form a structure termed the anti-terminator form [1]. This entry represents the conserved core of the complex structure involving helices 1-4. The structure of SAM riboswitch has been reported in PDBs: 2GIS, 2YDH, 2YGH, 3GX2, 3GX3, 3GX5, 3GX6, 3GX7, 3IQN, 3IQP, 3IQR, 3V7E, 4AOB, 4B5R, 4KQY, 5FJC, 5FK1, 5FK2, 5FK3, 5FK4, 5FK5, 5FK6, 5FKD, 5FKE, 5FKF, 5FKG, 5FKH, 7EAF [5-13]", "curation": {"author": "Griffiths-Jones SR, Gardner PP, Ontiveros-Palacios N", "seed_source": "Grundy F, Henkin T, PMID:10094622", "num_seed": 457, "num_full": 9625, "num_species": 4158, "type": "Cis-reg; riboswitch;", "structure_source": "Published; PMID:10094622"}, "cm": {"build_command": "cmbuild -F CM SEED", "calibrate_command": "cmcalibrate --mpi CM", "search_command": "cmsearch --cpu 4 --verbose --nohmmonly -T 30.00 -Z 2958934 CM SEQDB", "cutoffs": {"gathering": 44.4, "trusted": 44.4, "noise": 44.3}}, "release": {"date": "2026-01-16", "number": "15.1"}, "clan": {"acc": "CL00012", "id": "SAM"}}}