Faculty Collaboration Database

X-ray crystallographic characterization of the Co(II)-substituted Tris-bound form of the aminopeptidase from Aeromonas proteolytica. J Inorg Biochem 2007 Aug;101(8):1099-107

Date

06/19/2007

Pubmed ID

17574677

DOI

10.1016/j.jinorgbio.2007.03.010

Scopus ID

2-s2.0-34347397802 (requires institutional sign-in at Scopus site)   13 Citations

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.

Author List

Munih P, Moulin A, Stamper CC, Bennett B, Ringe D, Petsko GA, Holz RC

Author

Brian Bennett D.Phil. Professor and Chair in the Physics department at Marquette University

MESH terms used to index this publication - Major topics in bold

Aeromonas
Aminopeptidases
Binding Sites
Cobalt
Crystallization
Crystallography, X-Ray
Hydrogen Bonding
Metalloendopeptidases
Protein Folding
Tromethamine
Zinc