METAP1D Antibody – Mouse Polyclonal

The N-terminal methionine excision pathway is an essential process in which the N-terminal methionine is removed from many proteins, thus facilitating subsequent protein modification. In mitochondria, enzymes that catalyze this reaction are celled methionine aminopeptidases (MetAps, or MAPs; EC 3.4.11.18) (Serero et al., 2003 [PubMed 14532271]).[supplied by OMIM, Mar 2008]

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

By similarity. May play a role in colon tumorigenesis. Ref.2

Catalytic activity: Release of N-terminal amino acids, preferentially methionine, from peptides and arylamides. HAMAP-Rule MF_03174

Cofactor: 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 Fe2+-metalloproteases under physiological conditions, and the catalytically relevant metal-binding site has been assigned to the histidine-containing high-affinity site

By similarity. Ref.5

Subcellular location: Mitochondrion Ref.1.

Tissue specificity: Overexpressed in colon cancer cell lines and colon tumors as compared to normal tissues (at protein level). Ref.2

Sequence similarities: Belongs to the peptidase M24A family. Methionine aminopeptidase type 1 subfamily.

Caution: It is uncertain whether Met-1 or a Met upstream of this sequence is the initiator.

Biophysicochemical propertiesKinetic parameters:KM=573 µM for Met-pro-p-nitroanilide (at pH 8) Ref.5pH dependence:Optimum pH is 7.5-8.0.

Sequence caution: The sequence AAY55948.1 differs from that shown. Reason: Erroneous initiation.