Figure 1
The reaction catalysed by N-myristoyltransferase. (a) Top, scheme showing the ordered binding of myristoyl-CoA (MyrCoA) and the substrate protein followed by the ordered release of CoASH and the myristoylated product. Bottom, schematic of a step in the reaction mechanism showing the active site following binding of substrates and abstraction by the α-carboxylate of the C-terminal residue Leu421 of a proton from the α-amino group of Gly1 of the substrate protein. Thr303 and Asn169 form polar interactions with the amino group which attacks the carbonyl C atom of MyrCoA. The reaction intermediate is stabilized by interactions with an oxyanion hole formed by the amides of Leu167 and Phe168. This mechanism is adapted from Farazi et al. (2001). (b) Ribbon (left) and electrostatic surface (right) representations of LmNMT with bound MyrCoA and compound 7AH. The ligands bind in an extended cleft running across the molecule that is partially covered by the Ab loop. In the left-hand image the ligands are displayed as cylinders and coloured by atom type; in the right-hand image MyrCoA and 7AH are shown as green and light green spheres, respectively. |