1UDE

Crystal structure of the Inorganic pyrophosphatase from the hyperthermophilic archaeon Pyrococcus horikoshii OT3

Summary for 1UDE

• Entry DOI: 10.2210/pdb1ude/pdb
• Descriptor: Inorganic pyrophosphatase (2 entities in total)
• Functional Keywords: inorganic pyrophosphatase x-ray crystallographic analysis, hydrolase
• Biological source: Pyrococcus horikoshii
• Total number of polymer chains: 3
• Total formula weight: 68409.50

Authors

Liu, B.,Gao, R.,Zhou, W.,Bartlam, M.,Rao, Z. (deposition date: 2003-04-29, release date: 2004-01-20, Last modification date: 2023-12-27)

Primary citation

Liu, B.,Bartlam, M.,Gao, R.,Zhou, W.,Pang, H.,Liu, Y.,Feng, Y.,Rao, Z.
Crystal structure of the hyperthermophilic inorganic pyrophosphatase from the archaeon Pyrococcus horikoshii.
Biophys.J., 86:420-427, 2004

PubMed Abstract: A homolog to the eubacteria inorganic pyrophosphatase (PPase, EC 3.6.1.1) was found in the genome of the hyperthermophilic archaeon Pyrococcus horikoshii. This inorganic pyrophosphatase (Pho-PPase) grows optimally at 88 degrees C. To understand the structural basis for the thermostability of Pho-PPase, we have determined the crystal structure to 2.66 A resolution. The crystallographic asymmetric unit contains three monomers related by approximate threefold symmetry, and a hexamer is built up by twofold crystallographic symmetry. The main-chain fold of Pho-PPase is almost identical to that of the known crystal structure of the model from Sulfolobus acidocaldarius. A detailed comparison of the crystal structure of Pho-PPase with related structures from S. acidocaldarius, Thermus thermophilus, and Escherichia coli shows significant differences that may account for the difference in their thermostabilities. A reduction in thermolabile residues, additional aromatic residues, and more intimate association between subunits all contribute to the larger thermophilicity of Pho-PPase. In particular, deletions in two loops surrounding the active site help to stabilize its conformation, while ion-pair networks unique to Pho-PPase are located in the active site and near the C-terminus. The identification of structural features that make PPases more adaptable to extreme temperature should prove helpful for future biotechnology applications.

PubMed: 14695284
DOI: 10.1016/S0006-3495(04)74118-1

Experimental method

X-RAY DIFFRACTION (2.66 Å)