Cotranslationally removes the N-terminal methionine from nascent proteins. The N-terminal methionine is often cleaved when the second residue in the primary sequence is small and uncharged (Met-Ala-, Cys, Gly, Pro, Ser, Thr, or Val). Protects eukaryotic initiation factor EIF2S1 from translation-inhibiting phosphorylation by inhibitory kinases such as EIF2AK2/PKR and EIF2AK1/HCR. Plays a critical role in the regulation of protein synthesis. Release of N-terminal amino acids, preferentially methionine, from peptides and arylamides. Binds 2 divalent metal cations per subunit. Has a high-affinity and a low affinity metal-binding site. The true nature of the physiological cofactor is under debate. The enzyme is active with cobalt, zinc, manganese or divalent iron ions. Most likely, methionine aminopeptidases function as mononuclear Fe(2+)-metalloproteases under physiological conditions, and the catalytically relevant metal-binding site has been assigned to the histidine-containing high-affinity site. Binds EIF2S1 at low magnesium concentrations. Interacts strongly with the eIF-2 gamma-subunit EIF2S3. About 30% of expressed METAP2 associates with polysomes. Contains approximately 12 O-linked N-acetylglucosamine (GlcNAc) residues. O-glycosylation is required for EIF2S1 binding. Belongs to the peptidase M24A family. Methionine aminopeptidase eukaryotic type 2 subfamily.