3PBJ: Hydrolytic catalysis and structural stabilization in a designed metalloprotein

Citation:
Abstract
Metal ions are an important part of many natural proteins, providing structural, catalytic and electron transfer functions. Reproducing these functions in a designed protein is the ultimate challenge to our understanding of them. Here, we present an artificial metallohydrolase, which has been shown by X-ray crystallography to contain two different metal ions-a Zn(II) ion, which is important for catalytic activity, and a Hg(II) ion, which provides structural stability. This metallohydrolase displays catalytic activity that compares well with several characteristic reactions of natural enzymes. It catalyses p-nitrophenyl acetate (pNPA) hydrolysis with an efficiency only ~100-fold less than that of human carbonic anhydrase (CA)II and at least 550-fold better than comparable synthetic complexes. Similarly, CO(2) hydration occurs with an efficiency within ~500-fold of CAII. Although histidine residues in the absence of Zn(II) exhibit pNPA hydrolysis, miniscule apopeptide activity is observed for CO(2) hydration. The kinetic and structural analysis of this first de novo designed hydrolytic metalloenzyme reveals necessary design features for future metalloenzymes containing one or more metals.
PDB ID: 3PBJDownload
MMDB ID: 95345
PDB Deposition Date: 2010/10/20
Updated in MMDB: 2011/12
Experimental Method:
x-ray diffraction
Resolution: 2.2  Å
Similar Structures:
Biological Unit for 3PBJ: trimeric; determined by author
Molecular Components in 3PBJ
Label Count Molecule
Proteins (3 molecules)
3
Coil SER L9l-pen L23h
Molecule annotation
Chemicals (6 molecules)
1
3
2
1
3
1
4
1
* Click molecule labels to explore molecular sequence information.

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