Adds a myristoyl group to the N-terminal glycine residue of certain cellular proteins. Substrate specificity requires an N-terminal glycine in the nascent polypeptide substrates. Ser is present at position 5 in almost all known N-myristoyl proteins and Lys is commonly encountered at postion 6. Basic residues are preferred at positions 7 and 8. N-terminal glycyl-[protein] + tetradecanoyl-CoA = CoA + H(+) + N-tetradecanoylglycyl-[protein] Competitively inhibited by SC-58272, a peptidomimetic derived from the N-terminal sequence of a natural substrate. Monomer. Has an ordered Bi-Bi kinetic mechanism, with myristoyl-CoA binding taking place prior to peptide binding and CoA release occurring before acylated peptide release. Cooperative interactions between the acyl-CoA and peptide binding sites of NMT contribute to its extraordinary chain-length specificity. Belongs to the NMT family.