UniProt functional annotation for P0AE18

UniProt code: P0AE18.

Organism:		Escherichia coli (strain K12).
Taxonomy:		Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales; Enterobacteriaceae; Escherichia.
Function:		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). Requires deformylation of the N(alpha)-formylated initiator methionine before it can be hydrolyzed. {ECO:0000255|HAMAP- Rule:MF_01974, ECO:0000269|PubMed:20521764, ECO:0000269|PubMed:3027045}.
Catalytic activity:		Reaction=Release of N-terminal amino acids, preferentially methionine, from peptides and arylamides.; EC=3.4.11.18; Evidence={ECO:0000255|HAMAP-Rule:MF_01974, ECO:0000269|PubMed:17120228, ECO:0000269|PubMed:20521764, ECO:0000269|PubMed:3027045};
Cofactor:		Name=Co(2+); Xref=ChEBI:CHEBI:48828; Evidence={ECO:0000255|HAMAP-Rule:MF_01974, ECO:0000269|PubMed:10387007, ECO:0000269|PubMed:10460163, ECO:0000269|PubMed:10555963, ECO:0000269|PubMed:10736182, ECO:0000269|PubMed:17120228, ECO:0000269|PubMed:20017927}; Name=Zn(2+); Xref=ChEBI:CHEBI:29105; Evidence={ECO:0000255|HAMAP-Rule:MF_01974, ECO:0000269|PubMed:10460163}; Name=Mn(2+); Xref=ChEBI:CHEBI:29035; Evidence={ECO:0000255|HAMAP-Rule:MF_01974, ECO:0000269|PubMed:10460163, ECO:0000269|PubMed:16769889, ECO:0000269|PubMed:18093325}; Name=Fe(2+); Xref=ChEBI:CHEBI:29033; Evidence={ECO:0000255|HAMAP-Rule:MF_01974, ECO:0000269|PubMed:10460163, ECO:0000269|PubMed:10736182, ECO:0000269|PubMed:18785729, ECO:0000269|PubMed:22112844}; Note=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. {ECO:0000255|HAMAP-Rule:MF_01974, ECO:0000269|PubMed:10460163, ECO:0000269|PubMed:16769889, ECO:0000269|PubMed:18785729, ECO:0000269|PubMed:22112844};
Cofactor:		Name=Na(+); Xref=ChEBI:CHEBI:29101; Evidence={ECO:0000269|PubMed:10387007}; Note=Binds 1 sodium ion per subunit. The sodium ion has a structural role. {ECO:0000269|PubMed:10387007};
Biophysicochemical properties:		Kinetic parameters: KM=2.0 mM for a Met-Gly-Met-Met peptide (for the Fe(2+)-complexed enzyme) {ECO:0000269|PubMed:10460163, ECO:0000269|PubMed:12755633, ECO:0000269|PubMed:18855426, ECO:0000269|PubMed:19019076}; KM=1.3 mM for a Met-Gly-Met-Met peptide (for the Mn(2+)-complexed enzyme) {ECO:0000269|PubMed:10460163, ECO:0000269|PubMed:12755633, ECO:0000269|PubMed:18855426, ECO:0000269|PubMed:19019076}; KM=3.2 mM for a Met-Gly-Met-Met peptide (for the Co(2+)-complexed enzyme) {ECO:0000269|PubMed:10460163, ECO:0000269|PubMed:12755633, ECO:0000269|PubMed:18855426, ECO:0000269|PubMed:19019076}; Vmax=55 umol/min/mg enzyme (for the Fe(2+)-complexed enzyme) {ECO:0000269|PubMed:10460163, ECO:0000269|PubMed:12755633, ECO:0000269|PubMed:18855426, ECO:0000269|PubMed:19019076}; Vmax=77 umol/min/mg enzyme (for the Co(2+)-complexed enzyme) {ECO:0000269|PubMed:10460163, ECO:0000269|PubMed:12755633, ECO:0000269|PubMed:18855426, ECO:0000269|PubMed:19019076};
Subunit:		Monomer. {ECO:0000255|HAMAP-Rule:MF_01974, ECO:0000269|PubMed:10387007, ECO:0000269|PubMed:16769889}.
Similarity:		Belongs to the peptidase M24A family. Methionine aminopeptidase type 1 subfamily. {ECO:0000255|HAMAP-Rule:MF_01974}.

Annotations taken from UniProtKB at the EBI.