Capture of a third Mg2+ is essential for catalyzing DNA synthesis.
Gao, Y., Yang, W.(2016) Science 352: 1334-1337
- PubMed: 27284197 
- DOI: https://doi.org/10.1126/science.aad9633
- Primary Citation of Related Structures:  
5KFA, 5KFB, 5KFC, 5KFD, 5KFE, 5KFF, 5KFG, 5KFH, 5KFI, 5KFJ, 5KFK, 5KFL, 5KFM, 5KFN, 5KFO, 5KFP, 5KFQ, 5KFR, 5KFS, 5KFT, 5KFU, 5KFV, 5KFW, 5KFX, 5KFY, 5KFZ, 5KG0, 5KG1, 5KG2, 5KG3, 5KG4, 5KG5, 5KG6, 5KG7, 5L9X - PubMed Abstract: 
It is generally assumed that an enzyme-substrate (ES) complex contains all components necessary for catalysis and that conversion to products occurs by rearrangement of atoms, protons, and electrons. However, we find that DNA synthesis does not occur in a fully assembled DNA polymerase-DNA-deoxynucleoside triphosphate complex with two canonical metal ions bound ...