{"rfam": {"acc": "RF00380", "id": "Magnesium", "description": "M-box riboswitch aptamer (ykoK leader)", "comment": "M-box riboswitch, also know as ykoK leader is described as a metaloregulatory RNA that sense divalent metals and function as a genetic control element of genes related to divalent metal transport in bacteria. It was first reported upstream of the B.subtilis ykoK gene and genes with related functions in other bacteria [1]. The structure of the M-box was first reported in PDB 2QBZ [2], as a structure of three parallel helices, where P3 and P4 helixes form a coaxial stack that folds alongside P2 and P5. Six Mg2+ recognition sites were reported in 2QBZ, while in a second structure report in PDB 3PDR, the authors report another three sites of Mn2+ bound that been predicted from phosphorothioate substitution experiments and six more additional Mn2+ proposed from the analysis of the anomalous density in the sequence [3]. Phylogenetic analysis of the distribution of M-box RNAs across bacterial genomes revealed that M-box riboswitches are most often employed for the regulation of Mg2+ transporter genes [4]", "curation": {"author": "Moxon SJ, Ontiveros-Palacios N", "seed_source": "Barrick JE, Breaker RR", "num_seed": 159, "num_full": 1095, "num_species": 932, "type": "Cis-reg; riboswitch;", "structure_source": "Predicted; Barrick JE, Breaker RR"}, "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": 44.0, "trusted": 45.2, "noise": 36.5}}, "release": {"date": "2026-01-16", "number": "15.1"}, "clan": {"acc": null, "id": null}}}