Crystal Structure of Phosphatidylglycerophosphatase (Pgpase), a Putative Membrane-bound Lipid Phosphatase, Reveals a Novel Binuclear Metal Binding Site and Two "Proton Wires".
From: Biology Department, Brookhaven National Laboratory, Upton, New York 11973, USA.
Proteins
- Publish Date: Sep 2006
- ISSN: 1097-0134
- Volume: 64
- Issue: 4
- Pages: 851-62
- Medium: Internet
- Language: English
- Citation (JAMA): Kumaran Desigan, Bonanno Jeffrey B, Burley Stephen K, et al. Crystal Structure of Phosphatidylglycerophosphatase (Pgpase), a Putative Membrane-bound Lipid Phosphatase, Reveals a Novel Binuclear Metal Binding Site and Two "Proton Wires".. Proteins Sep 2006;64:851-62
Abstract
Phosphatidylglycerophosphatase (PGPase), an enzyme involved in lipid metabolism, catalyzes formation of phosphatidylglycerol from phosphatidylglycerophosphate. Phosphatidylglycerol is a multifunctional phospholipid, found in the biological membranes of many organisms. Here, we report the crystal structure of Listeria monocytogenes PGPase at 1.8 A resolution. PGPase, an all-helical molecule, forms a homotetramer. Each protomer contains an independent active site with two metal ions, Ca(2+) and Mg(2+), forming a hetero-binuclear center located in a hydrophilic cavity near the surface of the molecule. The binuclear center, conserved ligands, metal-bound water molecules, and an Asp-His dyad form the active site. The catalytic mechanism of this enzyme is likely to proceed via binuclear metal activated nucleophilic water. The binuclear metal-binding active-site environment of this structure should provide insights into substrate binding and metal-dependent catalysis. A long channel with inter-linked linear water chains, termed “proton wires,” is observed at the tetramer interface. Comparison of similar water chain structures in photosynthetic reaction centers (RCs), Cytochrome f, gramicidin, and bacteriorhodopsin, suggests that PGPase may conduct protons via proton wires.
Mesh Headings (Keywords): Amino Acid Sequence, Binding Sites, Calcium, Crystallization, Crystallography, X-Ray, Hydrogen Bonding, Listeria monocytogenes, Magnesium, Models, Molecular, Molecular Sequence Data, Phosphoric Monoester Hydrolases, Protein Structure, Quaternary, Protons, Sequence Alignment
Check for Full Text / PubMed Unique Identifier (PMID): 16838328
This abstract is part of PubMed, a service of the U.S. National Library of Medicine. PubMed includes more than 17 million citations from MEDLINE and other life science journals for biomedical articles. See Copyright and Disclaimers.
Linked medical terms appearing on this page are added by Healia to help readers find more information and are not part of the original PubMed document.
The data herein was last updated on July 8th, 2008 and may not reflect the most current and accurate data available from NLM.