2prd
From Proteopedia
(New page: 200px<br /><applet load="2prd" size="450" color="white" frame="true" align="right" spinBox="true" caption="2prd, resolution 2.0Å" /> '''CRYSTAL STRUCTURE OF ...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:2prd.jpg|left|200px]]<br /><applet load="2prd" size=" | + | [[Image:2prd.jpg|left|200px]]<br /><applet load="2prd" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2prd, resolution 2.0Å" /> | caption="2prd, resolution 2.0Å" /> | ||
'''CRYSTAL STRUCTURE OF INORGANIC PYROPHOSPHATASE FROM THERMUS THERMOPHILUS'''<br /> | '''CRYSTAL STRUCTURE OF INORGANIC PYROPHOSPHATASE FROM THERMUS THERMOPHILUS'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The 3-dimensional structure of inorganic pyrophosphatase from Thermus | + | The 3-dimensional structure of inorganic pyrophosphatase from Thermus thermophilus (T-PPase) has been determined by X-ray diffraction at 2.0 A resolution and refined to R = 15.3%. The structure consists of an antiparallel closed beta-sheet and 2 alpha-helices and resembles that of the yeast enzyme in spite of the large difference in size (174 and 286 residues, respectively), little sequence similarity beyond the active center (about 20%), and different oligomeric organization (hexameric and dimeric, respectively). The similarity of the polypeptide folding in the 2 PPases provides a very strong argument in favor of an evolutionary relationship between the yeast and bacterial enzymes. The same Greek-key topology of the 5-stranded beta-barrel was found in the OB-fold proteins, the bacteriophage gene-5 DNA-binding protein, toxic-shock syndrome toxin-1, and the major cold-shock protein of Bacillus subtilis. Moreover, all known nucleotide-binding sites in these proteins are located on the same side of the beta-barrel as the active center in T-PPase. Analysis of the active center of T-PPase revealed 17 residues of potential functional importance, 16 of which are strictly conserved in all sequences of soluble PPases. Their possible role in the catalytic mechanism is discussed on the basis of the present crystal structure and with respect to site-directed mutagenesis studies on the Escherichia coli enzyme. The observed oligomeric organization of T-PPase allows us to suggest a possible mechanism for the allosteric regulation of hexameric PPases. |
==About this Structure== | ==About this Structure== | ||
| - | 2PRD is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermus_thermophilus Thermus thermophilus] with SO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Inorganic_diphosphatase Inorganic diphosphatase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.6.1.1 3.6.1.1] Full crystallographic information is available from [http:// | + | 2PRD is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermus_thermophilus Thermus thermophilus] with <scene name='pdbligand=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Inorganic_diphosphatase Inorganic diphosphatase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.6.1.1 3.6.1.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2PRD OCA]. |
==Reference== | ==Reference== | ||
| Line 18: | Line 18: | ||
[[Category: hydrolase]] | [[Category: hydrolase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:32:17 2008'' |
Revision as of 16:32, 21 February 2008
|
CRYSTAL STRUCTURE OF INORGANIC PYROPHOSPHATASE FROM THERMUS THERMOPHILUS
Overview
The 3-dimensional structure of inorganic pyrophosphatase from Thermus thermophilus (T-PPase) has been determined by X-ray diffraction at 2.0 A resolution and refined to R = 15.3%. The structure consists of an antiparallel closed beta-sheet and 2 alpha-helices and resembles that of the yeast enzyme in spite of the large difference in size (174 and 286 residues, respectively), little sequence similarity beyond the active center (about 20%), and different oligomeric organization (hexameric and dimeric, respectively). The similarity of the polypeptide folding in the 2 PPases provides a very strong argument in favor of an evolutionary relationship between the yeast and bacterial enzymes. The same Greek-key topology of the 5-stranded beta-barrel was found in the OB-fold proteins, the bacteriophage gene-5 DNA-binding protein, toxic-shock syndrome toxin-1, and the major cold-shock protein of Bacillus subtilis. Moreover, all known nucleotide-binding sites in these proteins are located on the same side of the beta-barrel as the active center in T-PPase. Analysis of the active center of T-PPase revealed 17 residues of potential functional importance, 16 of which are strictly conserved in all sequences of soluble PPases. Their possible role in the catalytic mechanism is discussed on the basis of the present crystal structure and with respect to site-directed mutagenesis studies on the Escherichia coli enzyme. The observed oligomeric organization of T-PPase allows us to suggest a possible mechanism for the allosteric regulation of hexameric PPases.
About this Structure
2PRD is a Single protein structure of sequence from Thermus thermophilus with as ligand. Active as Inorganic diphosphatase, with EC number 3.6.1.1 Full crystallographic information is available from OCA.
Reference
Crystal structure of inorganic pyrophosphatase from Thermus thermophilus., Teplyakov A, Obmolova G, Wilson KS, Ishii K, Kaji H, Samejima T, Kuranova I, Protein Sci. 1994 Jul;3(7):1098-107. PMID:7920256
Page seeded by OCA on Thu Feb 21 18:32:17 2008
