TY - JOUR

T1 - Structure of the I-SceI nuclease complexed with its dsDNA target and three catalytic metal ions

AU - Prieto, Jesús

AU - Redondo, Pilar

AU - Merino, Nekane

AU - Villate, Maider

AU - Montoya, Guillermo

AU - Blanco, Francisco J

AU - Molina, Rafael

PY - 2016/6

Y1 - 2016/6

N2 - Homing endonucleases are highly specific DNA-cleaving enzymes that recognize and cleave long stretches of DNA. The engineering of these enzymes provides instruments for genome modification in a wide range of fields, including gene targeting. The homing endonuclease I-SceI from the yeast Saccharomyces cerevisiae has been purified after overexpression in Escherichia coli and its crystal structure has been determined in complex with its target DNA. In order to evaluate the number of ions that are involved in the cleavage process, thus determining the catalytic mechanism, crystallization experiments were performed in the presence of Mn(2+), yielding crystals that were suitable for X-ray diffraction analysis. The crystals belonged to the orthorhombic space group P212121, with unit-cell parameters a = 80.11, b = 80.57, c = 130.87 Å, α = β = γ = 90°. The self-rotation function and the Matthews coefficient suggested the presence of two protein-DNA complexes in the asymmetric unit. The crystals diffracted to a resolution limit of 2.9 Å using synchrotron radiation. From the anomalous data, it was determined that three cations are involved in catalysis and it was confirmed that I-SceI follows a two-metal-ion DNA-strand cleavage mechanism.

AB - Homing endonucleases are highly specific DNA-cleaving enzymes that recognize and cleave long stretches of DNA. The engineering of these enzymes provides instruments for genome modification in a wide range of fields, including gene targeting. The homing endonuclease I-SceI from the yeast Saccharomyces cerevisiae has been purified after overexpression in Escherichia coli and its crystal structure has been determined in complex with its target DNA. In order to evaluate the number of ions that are involved in the cleavage process, thus determining the catalytic mechanism, crystallization experiments were performed in the presence of Mn(2+), yielding crystals that were suitable for X-ray diffraction analysis. The crystals belonged to the orthorhombic space group P212121, with unit-cell parameters a = 80.11, b = 80.57, c = 130.87 Å, α = β = γ = 90°. The self-rotation function and the Matthews coefficient suggested the presence of two protein-DNA complexes in the asymmetric unit. The crystals diffracted to a resolution limit of 2.9 Å using synchrotron radiation. From the anomalous data, it was determined that three cations are involved in catalysis and it was confirmed that I-SceI follows a two-metal-ion DNA-strand cleavage mechanism.

KW - Catalysis

KW - DNA

KW - Deoxyribonucleases, Type II Site-Specific

KW - Metals

KW - Saccharomyces cerevisiae Proteins

KW - Journal Article

KW - Research Support, Non-U.S. Gov't

U2 - 10.1107/S2053230X16007512

DO - 10.1107/S2053230X16007512

M3 - Journal article

C2 - 27303901

VL - 72

SP - 473

EP - 479

JO - Acta Crystallographica Section F: Structural Biology Communications

JF - Acta Crystallographica Section F: Structural Biology Communications

SN - 2053-230X

IS - Pt 6

ER -