1xty
From Proteopedia
(New page: 200px<br /><applet load="1xty" size="450" color="white" frame="true" align="right" spinBox="true" caption="1xty, resolution 1.8Å" /> '''Crystal structure of ...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1xty.gif|left|200px]]<br /><applet load="1xty" size=" | + | [[Image:1xty.gif|left|200px]]<br /><applet load="1xty" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1xty, resolution 1.8Å" /> | caption="1xty, resolution 1.8Å" /> | ||
'''Crystal structure of Sulfolobus solfataricus peptidyl-tRNA hydrolase'''<br /> | '''Crystal structure of Sulfolobus solfataricus peptidyl-tRNA hydrolase'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The 3-D structure of the peptidyl-tRNA hydrolase from the archaea | + | The 3-D structure of the peptidyl-tRNA hydrolase from the archaea Sulfolobus solfataricus has been solved at 1.8 A resolution. Homologues of this enzyme are found in archaea and eucarya. Bacteria display a different type of peptidyl-tRNA hydrolase that is also encountered in eucarya. In solution, the S. solfataricus hydrolase behaves as a dimer. In agreement, the crystalline structure of this enzyme indicates the formation of a dimer. Each protomer is made of a mixed five-stranded beta-sheet surrounded by two groups of two alpha-helices. The dimer interface is mainly formed by van der Waals interactions between hydrophobic residues belonging to the two N-terminal alpha1 helices contributed by two protomers. Site-directed mutagenesis experiments were designed for probing the basis of specificity of the archaeal hydrolase. Among the strictly conserved residues within the archaeal/eucaryal peptidyl-tRNA hydrolase family, three residues, K18, D86, and T90, appear of utmost importance for activity. They are located in the N-part of alpha1 and in the beta3-beta4 loop. K18 and D86, which form a salt bridge, might play a role in the catalysis thanks to their acid and basic functions, whereas the OH group of T90 could act as a nucleophile. These observations clearly distinguish the active site of the archaeal/eucaryal hydrolases from that of the bacterial/eucaryal ones, where a histidine is believed to serve as the catalytic base. |
==About this Structure== | ==About this Structure== | ||
| - | 1XTY is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pyrococcus_abyssi Pyrococcus abyssi] with SO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Aminoacyl-tRNA_hydrolase Aminoacyl-tRNA hydrolase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.1.29 3.1.1.29] Full crystallographic information is available from [http:// | + | 1XTY is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pyrococcus_abyssi Pyrococcus abyssi] with <scene name='pdbligand=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Aminoacyl-tRNA_hydrolase Aminoacyl-tRNA hydrolase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.1.29 3.1.1.29] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XTY OCA]. |
==Reference== | ==Reference== | ||
| Line 23: | Line 23: | ||
[[Category: mixed beta sheet]] | [[Category: mixed beta sheet]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:58:36 2008'' |
Revision as of 13:58, 21 February 2008
|
Crystal structure of Sulfolobus solfataricus peptidyl-tRNA hydrolase
Overview
The 3-D structure of the peptidyl-tRNA hydrolase from the archaea Sulfolobus solfataricus has been solved at 1.8 A resolution. Homologues of this enzyme are found in archaea and eucarya. Bacteria display a different type of peptidyl-tRNA hydrolase that is also encountered in eucarya. In solution, the S. solfataricus hydrolase behaves as a dimer. In agreement, the crystalline structure of this enzyme indicates the formation of a dimer. Each protomer is made of a mixed five-stranded beta-sheet surrounded by two groups of two alpha-helices. The dimer interface is mainly formed by van der Waals interactions between hydrophobic residues belonging to the two N-terminal alpha1 helices contributed by two protomers. Site-directed mutagenesis experiments were designed for probing the basis of specificity of the archaeal hydrolase. Among the strictly conserved residues within the archaeal/eucaryal peptidyl-tRNA hydrolase family, three residues, K18, D86, and T90, appear of utmost importance for activity. They are located in the N-part of alpha1 and in the beta3-beta4 loop. K18 and D86, which form a salt bridge, might play a role in the catalysis thanks to their acid and basic functions, whereas the OH group of T90 could act as a nucleophile. These observations clearly distinguish the active site of the archaeal/eucaryal hydrolases from that of the bacterial/eucaryal ones, where a histidine is believed to serve as the catalytic base.
About this Structure
1XTY is a Single protein structure of sequence from Pyrococcus abyssi with as ligand. Active as Aminoacyl-tRNA hydrolase, with EC number 3.1.1.29 Full crystallographic information is available from OCA.
Reference
Crystal structure at 1.8 A resolution and identification of active site residues of Sulfolobus solfataricus peptidyl-tRNA hydrolase., Fromant M, Schmitt E, Mechulam Y, Lazennec C, Plateau P, Blanquet S, Biochemistry. 2005 Mar 22;44(11):4294-301. PMID:15766258
Page seeded by OCA on Thu Feb 21 15:58:36 2008
