2PRQ: X-ray Crystallographic Characterization Of The Co(ii)-substituted Tris-bound Form Of The Aminopeptidase From Aeromonas Proteolytica

Citation:
Abstract
The X-ray crystal structure of the Co(II)-loaded form of the aminopeptidase from Aeromonas proteolytica ([CoCo(AAP)]) was solved to 2.2A resolution. [CoCo(AAP)] folds into an alpha/beta globular domain with a twisted beta-sheet hydrophobic core sandwiched between alpha-helices, identical to [ZnZn(AAP)]. Co(II) binding to AAP does not introduce any major conformational changes to the overall protein structure and the amino acid residues ligated to the dicobalt(II) cluster in [CoCo(AAP)] are the same as those in the native Zn(II)-loaded structure with only minor perturbations in bond lengths. The Co(II)-Co(II) distance is 3.3A. Tris(hydroxymethyl)aminomethane (Tris) coordinates to the dinuclear Co(II) active site of AAP with one of the Tris hydroxyl oxygen atoms (O4) forming a single oxygen atom bridge between the two Co(II) ions. This is the only Tris atom coordinated to the metals with Co1-O and Co2-O bonds distances of 2.2 and 1.9A, respectively. Each of the Co(II) ions resides in a distorted trigonal bipyramidal geometry. This important structure bridges the gap between previous structural and spectroscopic studies performed on AAP and is discussed in this context.
PDB ID: 2PRQDownload
MMDB ID: 46660
PDB Deposition Date: 2007/5/4
Updated in MMDB: 2007/11
Experimental Method:
x-ray diffraction
Resolution: 2.15  Å
Source Organism:
Similar Structures:
Biological Unit for 2PRQ: monomeric; determined by author
Molecular Components in 2PRQ
Label Count Molecule
Protein (1 molecule)
1
Bacterial Leucyl Aminopeptidase
Molecule annotation
Chemicals (3 molecules)
1
2
2
1
* Click molecule labels to explore molecular sequence information.

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