4ALF: Pseudomonas fluorescens PhoX in complex with phosphate

Citation:
Abstract
Alkaline phosphatases play a crucial role in phosphate acquisition by microorganisms. To expand our understanding of catalysis by this class of enzymes, we have determined the structure of the widely occurring microbial alkaline phosphatase PhoX. The enzyme contains a complex active-site cofactor comprising two antiferromagnetically coupled ferric iron ions (Fe(3+)), three calcium ions (Ca(2+)), and an oxo group bridging three of the metal ions. Notably, the main part of the cofactor resembles synthetic oxide-centered triangular metal complexes. Structures of PhoX-ligand complexes reveal how the active-site metal ions bind substrate and implicate the cofactor oxo group in the catalytic mechanism. The presence of iron in PhoX raises the possibility that iron bioavailability limits microbial phosphate acquisition.
PDB ID: 4ALFDownload
MMDB ID: 108256
PDB Deposition Date: 2012/3/2
Updated in MMDB: 2014/09
Experimental Method:
x-ray diffraction
Resolution: 1.25  Å
Source Organism:
Similar Structures:
Biological Unit for 4ALF: monomeric; determined by author and by software (PISA)
Molecular Components in 4ALF
Label Count Molecule
Protein (1 molecule)
1
Alkaline Phosphatase Phox
Molecule annotation
Chemicals (16 molecules)
1
1
2
3
3
1
4
10
5
1
* Click molecule labels to explore molecular sequence information.

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