Human cytoplasmic ProX edits mischarged tRNAPro with amino acid but not tRNA specificity

2013 ◽  
Vol 450 (1) ◽  
pp. 243-252 ◽  
Author(s):  
Liang-Liang Ruan ◽  
Xiao-Long Zhou ◽  
Min Tan ◽  
En-Duo Wang
Keyword(s):  
Amino Acid ◽  
Protein Biosynthesis ◽  
Trna Synthetase ◽  
Main Body ◽  
Amino Acid Residues ◽  
Homologous Proteins ◽  
Gene Encoding ◽  
Trna Synthetases ◽  
Editing Domain ◽  
First Time

aaRSs (aminoacyl-tRNA synthetases) are responsible for ensuring the fidelity of the genetic code translation by accurately linking a particular amino acid to its cognate tRNA isoacceptor. To ensure accuracy of protein biosynthesis, some aaRSs have evolved an editing process to remove mischarged tRNA. The hydrolysis of the mischarged tRNA usually occurs in an editing domain, which is inserted into or appended to the main body of the aaRS. In addition, autonomous, editing domain-homologous proteins can also trans-edit mischarged tRNA in concert or in compensating for the editing function of its corresponding aaRS. The freestanding ProX is a homologue of the editing domain of bacterial ProRS (prolyl-tRNA synthetase). In the present study, we cloned for the first time a gene encoding HsProX (human cytoplasmic ProX) and purified the expressed recombinant protein. The catalytic specificity of HsProX for non-cognate amino acids and identity elements on tRNAPro for editing were also investigated. We found that HsProX could deacylate mischarged Ala-tRNAPro, but not Cys-HstRNAUGGPro, and specifically targeted the alanine moiety of Ala-tRNAPro. The importance of the CCA76 end of the tRNA for deacylation activity and key amino acid residues in HsProX for its editing function were also identified.

Histidyl-tRNA Synthetase

1999 ◽  
Vol 380 (6) ◽  
Author(s):  
W. Freist ◽  
J.F. Verhey ◽  
A. Rühlmann ◽  
D.H. Gauss ◽  
J.G. Arnez
Keyword(s):  
Amino Acid ◽  
Cell Metabolism ◽  
Trna Synthetase ◽  
Side Chain ◽  
Amino Acid Residues ◽  
Rheumatic Arthritis ◽  
Short Chain Length ◽  
Trna Synthetases ◽  
Catalytic Functions ◽  
Step Mechanism

AbstractHistidyl-tRNA synthetase (HisRS) is responsible for the synthesis of histidyl-transfer RNA, which is essential for the incorporation of histidine into proteins. This amino acid has uniquely moderate basic properties and is an important group in many catalytic functions of enzymes.A compilation of currently known primary structures of HisRS shows that the subunits of these homodimeric enzymes consist of 420–550 amino acid residues. This represents a relatively short chain length among aminoacyl-tRNA synthetases (aaRS), whose peptide chain sizes range from about 300 to 1100 amino acid residues.The crystal structures of HisRS from two organisms and their complexes with histidine, histidyl-adenylate and histidinol with ATP have been solved. HisRS fromThe aminoacylation reaction follows the standard two-step mechanism. HisRS also belongs to the group of aaRS that can rapidly synthesize diadenosine tetraphosphate, a compound that is suspected to be involved in several regulatory mechanisms of cell metabolism. Many analogs of histidine have been tested for their properties as substrates or inhibitors of HisRS, leading to the elucidation of structure-activity relationships concerning configuration, importance of the carboxy and amino group, and the nature of the side chain.HisRS has been found to act as a particularly important antigen in autoimmune diseases such as rheumatic arthritis or myositis. Successful attempts have been made to identify epitopes responsible for the complexation with such auto-antibodies.

scholarly journals Structural Basis for the Recognition of Isoleucyl-Adenylate and an Antibiotic, Mupirocin, by Isoleucyl-tRNA Synthetase

2001 ◽  
Vol 276 (50) ◽  
pp. 47387-47393 ◽  
Author(s):  
Takashi Nakama ◽  
Osamu Nureki ◽  
Shigeyuki Yokoyama
Keyword(s):  
Amino Acid ◽  
Thermus Thermophilus ◽  
High Energy ◽  
Trna Synthetase ◽  
Structural Basis ◽  
Amino Acid Residues ◽  
Trna Synthetases ◽  
Chemical Structures ◽  
Aminoacyl Trna Synthetases ◽  
The Common

An analogue of isoleucyl-adenylate (Ile-AMS) potently inhibits the isoleucyl-tRNA synthetases (IleRSs) from the three primary kingdoms, whereas the antibiotic mupirocin inhibits only the eubacterial and archaeal IleRSs, but not the eukaryotic enzymes, and therefore is clinically used against methicillin-resistantStaphylococcus aureus. We determined the crystal structures of the IleRS from the thermophilic eubacterium,Thermus thermophilus, in complexes with Ile-AMS and mupirocin at 3.0- and 2.5-Å resolutions, respectively. A structural comparison of the IleRS·Ile-AMS complex with the adenylate complexes of other aminoacyl-tRNA synthetases revealed the common recognition mode of aminoacyl-adenylate by the class I aminoacyl-tRNA synthetases. The Ile-AMS and mupirocin, which have significantly different chemical structures, are recognized by many of the same amino acid residues of the IleRS, suggesting that the antibiotic inhibits the enzymatic activity by blocking the binding site of the high energy intermediate, Ile-AMP. In contrast, the two amino acid residues that concomitantly recognize Ile-AMS and mupirocin are different between the eubacterial/archaeal IleRSs and the eukaryotic IleRSs. Mutagenic analyses revealed that the replacement of the two residues significantly changed the sensitivity to mupirocin.

Structural Relationship Between Human Salivary Histatins

1990 ◽  
Vol 69 (1) ◽  
pp. 2-6 ◽  
Author(s):  
R.F. Troxler ◽  
G.D. Offner ◽  
T. Xu ◽  
J.C. Vanderspek ◽  
F.G. Oppenheim
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequences ◽  
Amino Acid Residues ◽  
Homologous Proteins ◽  
Pathogenic Yeast ◽  
Histatin 5 ◽  
Structural Relationships ◽  
Carboxyl Terminal ◽  
Relationship Of ◽  
First Time

Histatins are a group of electrophoretically distinct histidine-rich polypeptides with microbicidal activity found in human parotid and submandibular gland secretions. Recently, we have shown that histatins 1, 3, and 5 are homologous proteins that consist of 38, 32, and 24 amino acid residues, respectively, and that these polypeptides kill the pathogenic yeast, Candida albicans. We now describe the isolation and structural characterization of histatins 2, 4, 6, and 7-12, the remaining members of this group of polypeptides. Histatin 2 was found to be identical to the carboxyl terminal 26 residues of histatin 1; histatin 4 was found to be identical to the carboxyl terminal 20 residues of histatin 3; and histatin 6 was found to be identical to histatin 5, but contained an additional carboxyl terminal arginine residue. The amino acid sequences of histatins 7-12 formally correspond to residues 12-24, 13-24, 12-25, 13-25, 5-11, and 5-12, respectively, of histatin 3, but could also arise proteolytically from histatin 5 or 6. These results establish, for the first time, the complete structural relationships between all members of this group of microbicidal proteins in human parotid saliva. The relationship of histatins to one another is discussed in the context of their genetic origin, biosynthesis and secretion into the oral cavity, and potential as reagents in anti-candidal studies.

A naturally occurring nonapeptide functionally compensates for the CP1 domain of leucyl-tRNA synthetase to modulate aminoacylation activity

2012 ◽  
Vol 443 (2) ◽  
pp. 477-484 ◽  
Author(s):  
Min Tan ◽  
Wei Yan ◽  
Ru-Juan Liu ◽  
Meng Wang ◽  
Xin Chen ◽  
...  
Keyword(s):  
Catalytic Efficiency ◽  
Trna Synthetase ◽  
Modular Construction ◽  
Aquifex Aeolicus ◽  
Trna Synthetases ◽  
Naturally Occurring ◽  
Aminoacyl Trna Synthetases ◽  
Editing Domain ◽  
Editing Activity ◽  
Shed Light

aaRSs (aminoacyl-tRNA synthetases) establish the rules of the genetic code by catalysing the formation of aminoacyl-tRNA. The quality control for aminoacylation is achieved by editing activity, which is usually carried out by a discrete editing domain. For LeuRS (leucyl-tRNA synthetase), the CP1 (connective peptide 1) domain is the editing domain responsible for hydrolysing mischarged tRNA. The CP1 domain is universally present in LeuRSs, except MmLeuRS (Mycoplasma mobile LeuRS). The substitute of CP1 in MmLeuRS is a nonapeptide (MmLinker). In the present study, we show that the MmLinker, which is critical for the aminoacylation activity of MmLeuRS, could confer remarkable tRNA-charging activity on the inactive CP1-deleted LeuRS from Escherichia coli (EcLeuRS) and Aquifex aeolicus (AaLeuRS). Furthermore, CP1 from EcLeuRS could functionally compensate for the MmLinker and endow MmLeuRS with post-transfer editing capability. These investigations provide a mechanistic framework for the modular construction of aaRSs and their co-ordination to achieve catalytic efficiency and fidelity. These results also show that the pre-transfer editing function of LeuRS originates from its conserved synthetic domain and shed light on future study of the mechanism.

scholarly journals Molecular Cloning and Characterization of Bifidobacterium bifidum 1,2-α-l-Fucosidase (AfcA), a Novel Inverting Glycosidase (Glycoside Hydrolase Family 95)

2004 ◽  
Vol 186 (15) ◽  
pp. 4885-4893 ◽  
Author(s):  
Takane Katayama ◽  
Akiko Sakuma ◽  
Takatoshi Kimura ◽  
Yutaka Makimura ◽  
Jun Hiratake ◽  
...  
Keyword(s):  
Amino Acid ◽  
Genomic Library ◽  
Bifidobacterium Bifidum ◽  
Glycoside Hydrolases ◽  
Glycoside Hydrolase Family ◽  
Amino Acid Residues ◽  
Gene Encoding ◽  
Sugar Chain ◽  
Hydrolysis Of

ABSTRACT A genomic library of Bifidobacterium bifidum constructed in Escherichia coli was screened for the ability to hydrolyze the α-(1→2) linkage of 2′-fucosyllactose, and a gene encoding 1,2-α-l-fucosidase (AfcA) was isolated. The afcA gene was found to comprise 1,959 amino acid residues with a predicted molecular mass of 205 kDa and containing a signal peptide and a membrane anchor at the N and C termini, respectively. A domain responsible for fucosidase activity (the Fuc domain; amino acid residues 577 to 1474) was localized by deletion analysis and then purified as a hexahistidine-tagged protein. The recombinant Fuc domain specifically hydrolyzed the terminal α-(1→2)-fucosidic linkages of various oligosaccharides and a sugar chain of a glycoprotein. The stereochemical course of the hydrolysis of 2′-fucosyllactose was determined to be inversion by using 1H nuclear magnetic resonance. The primary structure of the Fuc domain exhibited no similarity to those of any glycoside hydrolases (GHs) but showed high similarity to those of several hypothetical proteins in a database. Thus, it was revealed that the AfcA protein constitutes a novel inverting GH family (GH family 95).

scholarly journals Amino Acid Residues Required for Maturation, Cell Uptake, and Processing of Translation Inhibitor Microcin C

2006 ◽  
Vol 189 (5) ◽  
pp. 2114-2118 ◽  
Author(s):  
Teymur Kazakov ◽  
Anastasia Metlitskaya ◽  
Konstantin Severinov
Keyword(s):  
Amino Acid ◽  
Trna Synthetase ◽  
Trojan Horse ◽  
Cell Uptake ◽  
Amino Acid Residues ◽  
Peptide Moiety ◽  
Translation Inhibitor ◽  
Mutational Study ◽  
The Way

ABSTRACT Microcin C (McC), a peptide-nucleotide Trojan horse antibiotic, targets aspartyl-tRNA synthetase. We present the results of a systematic mutational study of the 7-amino-acid ribosomally synthesized peptide moiety of McC. Our results define amino acid positions important for McC maturation and cell uptake and processing and open the way for creation of more potent McC-based inhibitors.

scholarly journals RPC53 encodes a subunit of Saccharomyces cerevisiae RNA polymerase C (III) whose inactivation leads to a predominantly G1 arrest.

1992 ◽  
Vol 12 (10) ◽  
pp. 4314-4326 ◽  
Author(s):  
C Mann ◽  
J Y Micouin ◽  
N Chiannilkulchai ◽  
I Treich ◽  
J M Buhler ◽  
...  
Keyword(s):  
Cell Division ◽  
Amino Acid ◽  
Rna Polymerase ◽  
Essential Gene ◽  
Temperature Sensitive ◽  
G1 Arrest ◽  
Restrictive Temperature ◽  
Amino Acid Residues ◽  
Gene Encoding ◽  
Carboxy Terminal

RPC53 is shown to be an essential gene encoding the C53 subunit specifically associated with yeast RNA polymerase C (III). Temperature-sensitive rpc53 mutants were generated and showed a rapid inhibition of tRNA synthesis after transfer to the restrictive temperature. Unexpectedly, the rpc53 mutants preferentially arrested their cell division in the G1 phase as large, round, unbudded cells. The RPC53 DNA sequence is predicted to code for a hydrophilic M(r)-46,916 protein enriched in charged amino acid residues. The carboxy-terminal 136 amino acids of C53 are significantly similar (25% identical amino acid residues) to the same region of the human BN51 protein. The BN51 cDNA was originally isolated by its ability to complement a temperature-sensitive hamster cell mutant that undergoes a G1 cell division arrest, as is true for the rpc53 mutants.

scholarly journals The molecular aetiology of tRNA synthetase depletion: induction of a GCN4 amino acid starvation response despite homeostatic maintenance of charged tRNA levels

2020 ◽  
Vol 48 (6) ◽  
pp. 3071-3088
Author(s):  
Matthew R McFarland ◽  
Corina D Keller ◽  
Brandon M Childers ◽  
Stephen A Adeniyi ◽  
Holly Corrigall ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Neurological Disorders ◽  
Trna Synthetase ◽  
Northern Blotting ◽  
Amino Acid Starvation ◽  
Starvation Response ◽  
Kinase Activation ◽  
Trna Synthetases ◽  
Starvation Conditions

Abstract During protein synthesis, charged tRNAs deliver amino acids to translating ribosomes, and are then re-charged by tRNA synthetases (aaRS). In humans, mutant aaRS cause a diversity of neurological disorders, but their molecular aetiologies are incompletely characterised. To understand system responses to aaRS depletion, the yeast glutamine aaRS gene (GLN4) was transcriptionally regulated using doxycycline by tet-off control. Depletion of Gln4p inhibited growth, and induced a GCN4 amino acid starvation response, indicative of uncharged tRNA accumulation and Gcn2 kinase activation. Using a global model of translation that included aaRS recharging, Gln4p depletion was simulated, confirming slowed translation. Modelling also revealed that Gln4p depletion causes negative feedback that matches translational demand for Gln-tRNAGln to aaRS recharging capacity. This maintains normal charged tRNAGln levels despite Gln4p depletion, confirmed experimentally using tRNA Northern blotting. Model analysis resolves the paradox that Gln4p depletion triggers a GCN4 response, despite maintenance of tRNAGln charging levels, revealing that normally, the aaRS population can sequester free, uncharged tRNAs during aminoacylation. Gln4p depletion reduces this sequestration capacity, allowing uncharged tRNAGln to interact with Gcn2 kinase. The study sheds new light on mutant aaRS disease aetiologies, and explains how aaRS sequestration of uncharged tRNAs can prevent GCN4 activation under non-starvation conditions.

scholarly journals Identification of potential amino acid residues supporting anticodon recognition in yeast methionyl-tRNA synthetase

FEBS Letters ◽  
1991 ◽  
Vol 289 (2) ◽  
pp. 217-220 ◽  
Author(s):  
Laurence Despons ◽  
Philippe Walter ◽  
Bruno Senger ◽  
Jean-Pierre Ebel ◽  
Franco Fasiolo
Keyword(s):  
Amino Acid ◽  
Trna Synthetase ◽  
Amino Acid Residues ◽  
Methionyl Trna Synthetase

scholarly journals Structural and mutational studies of the amino acid-editing domain from archaeal/eukaryal phenylalanyl-tRNA synthetase

2006 ◽  
Vol 103 (40) ◽  
pp. 14744-14749 ◽  
Author(s):  
H. M. Sasaki ◽  
S.-i. Sekine ◽  
T. Sengoku ◽  
R. Fukunaga ◽  
M. Hattori ◽  
...  
Keyword(s):  
Amino Acid ◽  
Trna Synthetase ◽  
Amino Acid Editing ◽  
Editing Domain
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