1xty
From Proteopedia
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| , resolution 1.8Å | |||||||
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| Ligands: | |||||||
| Gene: | pth (Pyrococcus abyssi) | ||||||
| Activity: | Aminoacyl-tRNA hydrolase, with EC number 3.1.1.29 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
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. 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 Mar 20 15:14:29 2008
