Taxonomic distribution of proteins containing AMP_N domains

The tree below includes only several representative species and genera. The complete taxonomic breakdown of all proteins containing AMP_N domains can be accessed here. Click the counts or percentage values to display the corresponding proteins.

Structure and mechanism of a proline-specific aminopeptidase fromEscherichia coli.

Wilce MC, Bond CS, Dixon NE, Freeman HC, Guss JM, Lilley PE, Wilce JA
Proc Natl Acad Sci U S A. 1998; 95: 3472-7

The structure of the proline-specific aminopeptidase (EC 3.4.11.9) fromEscherichia coli has been solved and refined for crystals of the nativeenzyme at a 2.0-A resolution, for a dipeptide-inhibited complex at 2.3-Aresolution, and for a low-pH inactive form at 2.7-A resolution. Theprotein crystallizes as a tetramer, more correctly a dimer of dimers, atboth high and low pH, consistent with observations from analyticalultracentrifuge studies that show that the protein is a tetramer underphysiological conditions. The monomer folds into two domains. The activesite, in the larger C-terminal domain, contains a dinuclear manganesecenter in which a bridging water molecule or hydroxide ion appears poisedto act as the nucleophile in the attack on the scissile peptide bond ofXaa-Pro. The metal-binding residues are located in a single subunit, butthe residues surrounding the active site are contributed by threesubunits. The fold of the protein resembles that of creatineamidinohydrolase (creatinase, not a metalloenzyme). The C-terminalcatalytic domain is also similar to the single-domain enzyme methionineaminopeptidase that has a dinuclear cobalt center.