{"rfam": {"acc": "RF00032", "id": "Histone3", "description": "Histone 3' UTR stem-loop", "comment": "The mRNAs of metazoan histone genes lack a poly-A tail. 3' end processing occurs at a site between a highly conserved stem-loop (modelled by this family) and a purine rich region around 20 nts downstream (the histone downstream element, or HDE). The stem-loop is bound by a 31 kDa stem-loop binding protein (SLBP - also termed the histone hairpin binding protein, or HBP). Together with U7 snRNA binding of the HDE, SLBP binding nucleate s the formation of the processing complex. The histone 3' UTR stem-loop is also involved in nucleocytoplasmic transport of the mRNA, and in stability regulation and translation efficiency in the cytoplasm. The structure of stem loop of mRNA of metazoan histone genes has been reported in PDB 1JU7, 1JWC, 4L8R, 4QOZ, 4TUW, 4TUX and 4TV0 [4,5,6]", "curation": {"author": "Gardner PP, Ontiveros-Palacios N", "seed_source": "Published; PMID:17998288", "num_seed": 50, "num_full": 44596, "num_species": 976, "type": "Cis-reg;", "structure_source": "Published; PMID:17998288"}, "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": 34.0, "trusted": 34.0, "noise": 33.9}}, "release": {"date": "2026-01-16", "number": "15.1"}, "clan": {"acc": null, "id": null}}}