EPSP synthase - the target of Round-Up

This plant enzyme is part of the cellular machinery that synthesizes essential amino acids, which are building blocks of proteins and precursors to many of the chemical compounds that plants make. Round-up binds to this enzyme and prevents it from working - killing the plant. Round-Up resistant plants have a variant of this enzyme that prevents Round-Up from binding and allowing the plants to live, even if they are sprayed with this herbicide.