Article

Mechanistic insight into the catalytic activity of ββα-metallonucleases from computer simulations: Vibrio vulnificus periplasmic nuclease as a test case.

Department of Pharmacology, Universidad de Alcalá, 28871 Alcalá de Henares, Madrid, Spain.
ChemBioChem (Impact Factor: 3.06). 11/2011; 12(17):2615-22. DOI: 10.1002/cbic.201100485
Source: PubMed

ABSTRACT Using information from wild-type and mutant Vibrio vulnificus nuclease (Vvn) and I-PpoI homing endonuclease co-crystallized with different oligodeoxynucleotides, we have built the complex of Vvn with a DNA octamer and carried out a series of simulations to dissect the catalytic mechanism of this metallonuclease in a stepwise fashion. The distinct roles played in the reaction by individual active site residues, the metal cation and water molecules have been clarified by using a combination of classical molecular dynamics simulations and quantum mechanical calculations. Our results strongly support the most parsimonious catalytic mechanism, namely one in which a single water molecule from bulk solvent is used to cleave the phosphodiester bond and protonate the 3'-hydroxylate leaving group.

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