Literature summary for 1.15.1.1 extracted from

Azadmanesh, J.; Trickel, S.R.; Borgstahl, G.E.O.
Substrate-analog binding and electrostatic surfaces of human manganese superoxide dismutase (2017), J. Struct. Biol., 199, 68-75 .

Cloned(Commentary)

Cloned (Comment)	Organism
gene SOD2, recombinant expression in Escherichia coli	Homo sapiens

Crystallization (Commentary)

Crystallization (Comment)	Organism
purified enzyme MnSOD in complex with azide, hanging-drop vapor diffusion, mixing of 0.001 ml of 21 mg/ml protein solution with 0.001 ml of reservoir solution 1.8 M potassium phosphate, pH 7.8, at room temperature for1 day, to obtain the azide complex, 0.002 ml of reservoir containing 200 mM sodium azide are added to drops of 6 day crystals, X-ray diffraction structure determination and analysis at 1.77-1.82 A resolution	Homo sapiens

Crystallization (Comment)

Organism

purified enzyme MnSOD in complex with azide, hanging-drop vapor diffusion, mixing of 0.001 ml of 21 mg/ml protein solution with 0.001 ml of reservoir solution 1.8 M potassium phosphate, pH 7.8, at room temperature for1 day, to obtain the azide complex, 0.002 ml of reservoir containing 200 mM sodium azide are added to drops of 6 day crystals, X-ray diffraction structure determination and analysis at 1.77-1.82 A resolution

Homo sapiens

Inhibitors

Inhibitors	Comment	Organism	Structure
azide	the azide ion acts as a strong competitive inhibitor for SOD by binding directly to the active site metal. Azide is bound end-on at the sixth coordinate position of the manganese ion. Tetrameric electrostatic surfaces are calculated incorporating accurate partial charges for the active site in three states, including a state with superoxide coordinated to the metal using the position of azide as a model	Homo sapiens

Metals/Ions

Metals/Ions	Comment	Organism	Structure
Mn2+	a Mn-SOD	Homo sapiens

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
2 superoxide + 2 H+	Homo sapiens	-	O2 + H2O2	-	?

Organism

Organism	UniProt	Comment	Textmining
Homo sapiens	P04179	-	-

Purification (Commentary)

Purification (Comment)	Organism
soluble recombinant enzyme SOD2 from Escherichia coli cell-free extract by dialysis, anion exchange chromatography, again dialysis, and ultrafiltration	Homo sapiens

Reaction

Reaction	Comment	Organism	Reaction ID
2 superoxide + 2 H+ = O2 + H2O2	electrostatic guidance of anionic substrate to the active site, detailed overview. Generation of a model for electrostatic-mediated diffusion, and efficient binding of superoxide for catalysis	Homo sapiens	a

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
2 superoxide + 2 H+	-	Homo sapiens	O2 + H2O2	-	?

Subunits

Subunits	Comment	Organism
tetramer	-	Homo sapiens

Synonyms

Synonyms	Comment	Organism
manganese superoxide dismutase	-	Homo sapiens
MnSOD	-	Homo sapiens
SOD2	-	Homo sapiens

General Information

General Information	Comment	Organism
additional information	the putative binding position of superoxide is determined from the crystal structure of the enzyme in complex with azide, providing a model for binding to the active site. Facilitation of the anionic ligand to the active site pit via a valley of positively-charged surface patches. Surrounding ridges of negative charge help guide the superoxide anion. Within the active site pit, Arg173 and Glu162 further guide and align superoxide for efficient catalysis. Superoxide coordination at the sixth position causes the electrostatic surface of the active site pit to become nearly neutral. Generation of a model for electrostatic-mediated diffusion, and efficient binding of superoxide for catalysis. The active site manganese ion is coordinated by His26, His74, Asp159, His163, and a single oxygen, typically thought to be a water or hydroxide ion. These ligands are referred to as the inner-sphere residues. Outer-sphereresidues surround the inner-sphere and include His30, Tyr34, Phe77, Trp78, Trp123, Gln143, Trp161 and, from across the dimer interface, Glu162. Distorted five-coordinate trigonal bipyramidal active site geometry of native human MnSOD, overview	Homo sapiens