MgRNA: Classification of Mg2+ binding sites in RNA crystal structures Back to Classification Home Download this subset in: CSV, XML, JSON List of Mg2+ binding sites in structure 3i1n 3I1N (3.19Å) -- RIBOSOME : Crystal structure of the e. coli 70s ribosome in an intermediate state of ratcheting List of all 141 Mg2+ binding sites in the PDB structure 3i1n in the full dataset (switch to benchmark dataset) Sites in the table can be ordered by the following fields by clicking the column header: "benchmark dataset", "Coordination Number", "Qv #", "Qs #", "Qe #", "Site type" or "Mg2+ ID" Page 2 of 8 | « Previous | Next » | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8

Mg2+ ion Site type Validation parameters PDB ID Mg2+ ID Coordination Number Qv # Qs # Qe # benchmark dataset 3i1n A2920 2Pout·Rout·3Bout 6   0.76   0.98   0.71 yes 3i1n A2921 2Pout·3Bout 6   0.75   0.99   0.86 yes 3i1n A2922 cis-2Oph 6   0.81   0.76   0.51 yes 3i1n A2923 2Nb 6   0.86   0.90   0.89 yes 3i1n A2924 4Bout 6   0.75   0.99   0.32 no 3i1n A2925 Ob 6   0.96   0.95   0.54 yes 3i1n A2926 trans-2Oph 6   0.95   0.87   0.94 yes 3i1n A2927 cis-2Oph 5   0.70   0.70   0.84 yes 3i1n A2928 cis-2Oph 6   0.87   0.88   0.51 yes 3i1n A2929 Bout 6   0.75   0.98   0.45 no 3i1n A2930 Oph 6   0.88   0.91   0.64 yes 3i1n A2931 Oph·2Pout 6   0.90   0.93   0.75 yes 3i1n A2932 Oph·Pout 5   0.75   0.80   0.91 yes 3i1n A2933 2Pout 6   0.75   0.99   0.99 yes 3i1n A2934 mer-3Oph 6   0.71   0.88   0.49 no 3i1n A2935 cis-2Oph 6   0.82   0.79   0.88 yes 3i1n A2936 Oph·Pout 6   0.87   0.87   0.19 no 3i1n A2937 fac-3Oph 6   0.54   0.77   0.25 no 3i1n A2938 cis-2Oph 6   0.79   0.77   0.46 no 3i1n A2939 Oph·Pout 6   0.94   0.94   0.36 no

^# Validation parameters Q_v, Q_s, Q_e are defined in the range of 0 to 1, with 0 indicating poorest reliability and higher value indicating a more reliable site
Q_v measures the agreement of the inner-sphere bond valence summation with the oxidation state of Mg²⁺ (+2)
Q_s measures the geometrical symmetry of the ligands distribution around the Mg²⁺ required for octahedral geometry
Q_e measures the agreement of the isotropic atomic displacement (B) factor and occupancy of the Mg²⁺ compared to those of all atoms in its environment

Site type used in the classification is a string abbreviation of ligand composition in Mg2+ coordination sphere
Abbreviations used for Mg2+ "Site type"	Mg2+ inner-sphere ligands	Geometry for inner-sphere OP	Mg2+ outer-sphere moieties
	Oph phosphate oxygen (OP1/OP2) Or ribose oxygen (O2'/O4')      or oxygen bridging phosphate and ribose (O3'/O5') Ob nucleobase oxygen      Nb nucleobase nitrogen	cis- two OP ligands adopt cis- isoform trans- two OP ligands adopt trans- isoform fac- three OP ligands adopt fac- isoform mer- three OP ligands adopt mer- isoform	Pout phosphate moiety Rout ribose moiety Bout nucleobase moiety
Reference:	Zheng H, Shabalin IG, Handing KB, Bujnicki JM, Minor W. (2015) Magnesium binding architectures in RNA crystal structures: validation, binding preferences, classification, and motif detection. Nucleic Acid Research 43(7):3789-801 [Pubmed].

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