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 1kqs 1KQS (3.1Å) -- RIBOSOME : The haloarcula marismortui 50s complexed with a pretranslocational intermediate in protein synthesis List of all 117 Mg2+ binding sites in the PDB structure 1kqs 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 3 of 6 | « Previous | Next » | 1 | 2 | 3 | 4 | 5 | 6

Mg2+ ion Site type Validation parameters PDB ID Mg2+ ID Coordination Number Qv # Qs # Qe # benchmark dataset 1kqs 08044 Mg2+ bound by non-RNA 5   0.38   0.70   0.97 no 1kqs 08055 2Pout 6   0.32   0.71   0.74 no 1kqs 08089 cis-2Oph·Nb 6   0.63   0.72   0.82 yes 1kqs 08088 poly-nuclear Mg2+ site 6   0.52   0.73   0.99 yes 1kqs 08052 trans-2Oph 6   0.71   0.73   0.76 yes 1kqs 08081 mer-3Oph 5   0.60   0.73   0.96 yes 1kqs 08056 Mg2+ bound by non-RNA 6   0.94   0.73   0.99 yes 1kqs 08039 Oph·Pout 6   0.87   0.74   0.92 yes 1kqs 08107 cis-2Oph 6   0.89   0.75   0.83 yes 1kqs 08014 Oph·Or 6   0.90   0.75   0.92 yes 1kqs 08048 cis-2Oph 6   0.79   0.75   0.68 yes 1kqs 08083 Oph·Pout 6   0.95   0.77   0.78 yes 1kqs 08029 cis-2Oph 6   0.64   0.77   0.61 yes 1kqs 08112 Nb 6   0.58   0.78   0.88 yes 1kqs 08068 Oph·2Pout 6   0.96   0.78   0.97 yes 1kqs 08096 poly-nuclear Mg2+ site 6   0.50   0.79   0.85 yes 1kqs 08037 Oph·3Pout 6   0.89   0.79   0.98 yes 1kqs 08003 fac-3Oph 6   0.94   0.80   0.95 yes 1kqs 08002 cis-2Oph·Ob 6   0.80   0.80   0.71 yes 1kqs 08084 Oph·Pout 6   0.86   0.80   0.61 yes

^# 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].

---

Developed by Heping Zheng and Ivan Shabalin at Minor lab (http://olenka.med.virginia.edu/CrystUVa/)
For any help please contact <dust@iwonka.med.virginia.edu>