Aminoacyl-tRNA synthetases: Versatile players in the changing theater of translation

Francklyn, Christopher S.; Perona, John J.; Puetz, Joern; Hou, Ya‐Ming

doi:10.1017/s1355838202021180

Cited by 80 publications

(58 citation statements)

References 82 publications

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“…Therefore, we concluded that U70 has a relevant role in A-PGS substrate recognition. In addition, specific substrate discrimination also might include dynamic interaction among aa-PGS and the overall tRNA substrate as exemplified for other transient protein/tRNA complexes (22,23). Future cocrystallization experiments in the presence of sophisticated nonhydrolyzable aminoacyl-tRNA analogs might reveal such conformational rearrangements with relevance for the specific recognition of Ala-tRNA Ala or Lys-tRNA Lys .…”

Section: Resultsmentioning

confidence: 99%

Structures of two bacterial resistance factors mediating tRNA-dependent aminoacylation of phosphatidylglycerol with lysine or alanine

Hebecker

Krausze

Hasenkampf

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

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The cytoplasmic membrane is probably the most important physical barrier between microbes and the surrounding habitat. Aminoacylation of the polar head group of the phospholipid phosphatidylglycerol (PG) catalyzed by Ala-tRNA Ala -dependent alanyl-phosphatidylglycerol synthase (A-PGS) or by Lys-tRNA Lys -dependent lysyl-phosphatidylglycerol synthase (L-PGS) enables bacteria to cope with cationic peptides that are harmful to the integrity of the cell membrane. Accordingly, these synthases also have been designated as multiple peptide resistance factors (MprF). They consist of a separable C-terminal catalytic domain and an N-terminal transmembrane flippase domain. Here we present the X-ray crystallographic structure of the catalytic domain of A-PGS from the opportunistic human pathogen Pseudomonas aeruginosa. In parallel, the structure of the related lysyl-phosphatidylglycerol-specific L-PGS domain from Bacillus licheniformis in complex with the substrate analog L-lysine amide is presented. Both proteins reveal a continuous tunnel that allows the hydrophobic lipid substrate PG and the polar aminoacyl-tRNA substrate to access the catalytic site from opposite directions. Substrate recognition of A-PGS versus L-PGS was investigated using misacylated tRNA variants. The structural work presented here in combination with biochemical experiments using artificial tRNA or artificial lipid substrates reveals the tRNA acceptor stem, the aminoacyl moiety, and the polar head group of PG as the main determinants for substrate recognition. A mutagenesis approach yielded the complementary amino acid determinants of tRNA interaction. These results have broad implications for the design of L-PGS and A-PGS inhibitors that could render microbial pathogens more susceptible to antimicrobial compounds.A-PGS | L-PGS | MprF | structure | tRNA

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Section: Resultsmentioning

confidence: 99%

Structures of two bacterial resistance factors mediating tRNA-dependent aminoacylation of phosphatidylglycerol with lysine or alanine

Hebecker

Krausze

Hasenkampf

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

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“…First, the 5′-monophosphorylated tRNA that results from RNase P cleavage of pre-tRNA His is activated using ATP, creating a 5 0 -adenylylatedtRNA His intermediate. This adenylylation step mirrors the activation step in aminoacyl-tRNA synthetases in which the amino acid receives an AMP moiety prior to being charged on the cognate tRNA (15,16). In the second step, the 3′-hydroxyl of GTP attacks the activated intermediate, yielding triphosphorylated Fig.…”

Section: G-1 Addition | Reverse Polymerase | Trna Modificationmentioning

confidence: 88%

tRNA ^His guanylyltransferase (THG1), a unique 3′-5′ nucleotidyl transferase, shares unexpected structural homology with canonical 5′-3′ DNA polymerases

Hyde

Eckenroth

Smith

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

131

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All known DNA and RNA polymerases catalyze the formation of phosphodiester bonds in a 5′ to 3′ direction, suggesting this property is a fundamental feature of maintaining and dispersing genetic information. The tRNA His guanylyltransferase (Thg1) is a member of a unique enzyme family whose members catalyze an unprecedented reaction in biology: 3′-5′ addition of nucleotides to nucleic acid substrates. The 2.3-Å crystal structure of human THG1 (hTHG1) reported here shows that, despite the lack of sequence similarity, hTHG1 shares unexpected structural homology with canonical 5′-3′ DNA polymerases and adenylyl/guanylyl cyclases, two enzyme families known to use a two-metal-ion mechanism for catalysis. The ability of the same structural architecture to catalyze both 5′-3′ and 3′-5′ reactions raises important questions concerning selection of the 5′-3′ mechanism during the evolution of nucleotide polymerases. G-1 addition | reverse polymerase | tRNA modificationA ll nucleotide polymerases, including DNA and RNA polymerases, reverse transcriptase, and telomerase, catalyze nucleotide addition in the 5′ to 3′ direction. The reaction involves the nucleophilic attack of a polynucleotide terminal 3′-OH onto the α-phosphate of an incoming nucleotide, followed by release of the pyrophosphate moiety. Although the 5′ to 3′ direction has been adopted by all polymerases and transferases described to date, there is one notable exception: the enzyme tRNA His guanylyltransferase (Thg1). Thg1 catalyzes the highly unusual 3′-5′ addition of a single guanine to the 5′-end of tRNA His (1, 2). This reaction is an obligatory step in the maturation of this tRNA because the extra 5′ base, G −1 , constitutes a primary identity element for the aminoacyl-tRNA synthetase (HisRS) that attaches the amino acid histidine to the 3′-end of the tRNA (3-9). Thg1 is thus essential for maintaining the fidelity of protein synthesis. Consistent with the critical nature of the G −1 residue, THG1 is an essential gene in yeast and RNAi-mediated silencing of the Thg1 homolog in human cells results in severe cell-cycle progression and growth defects (2, 10, 11). Thg1 is widely conserved throughout eukarya, and Thg1 homologs are present in many archaea and bacteria.In eukarya, G −1 addition occurs opposite a universally conserved A 73 and thus is the result of a nontemplated 3′-5′ addition reaction. In addition, yeast Thg1 catalyzes a second reaction in vitro, extending tRNA substrates in the 3′-5′ direction in a template-directed manner driven by Watson-Crick pairing (12). Thg1 enzymes in archaea also catalyze template-dependent 3′-5′ addition, but do not catalyze nontemplated G −1 addition (13), suggesting that the templated 3′-5′ addition reaction likely represents an ancestral activity of the earliest Thg1 family members.The 3′-5′ addition of G −1 to tRNA His occurs via three chemical reactions, all catalyzed by Thg1 (2, 14) (Fig. 1). First, the 5′-monophosphorylated tRNA that results from RNase P cleavage of pre-tRNA His is activated using ATP, creating a 5...

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“…Aminoacyl-tRNA synthetases (aaRSs) 2 covalently couple tRNAs with their cognate amino acids in a two-step aminoacylation reaction that provides the precursors for ribosomal protein synthesis ( Fig. 1) (1, 2).…”

mentioning

confidence: 99%

Kinetic Partitioning between Synthetic and Editing Pathways in Class I Aminoacyl-tRNA Synthetases Occurs at Both Pre-transfer and Post-transfer Hydrolytic Steps

Cvetešić

Perona

Gruić-Sovulj

2012

Journal of Biological Chemistry

Self Cite

121

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Background: Error-prone aminoacyl-tRNA synthetases clear noncognate aminoacyl-adenylates and misacylated tRNAs within synthetic and editing sites, respectively. Results: Product release limits the rate of post-transfer editing by leucyl-tRNA synthetase. Conclusion: Kinetic partitioning of misacylated tRNA determines the relative contribution of cis and trans editing. Significance: In contrast to DNA polymerases, error correction in class I tRNA synthetases relies on substrate selection by the editing site.

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Aminoacyl-tRNA synthetases: Versatile players in the changing theater of translation

Cited by 80 publications

References 82 publications

Structures of two bacterial resistance factors mediating tRNA-dependent aminoacylation of phosphatidylglycerol with lysine or alanine

Structures of two bacterial resistance factors mediating tRNA-dependent aminoacylation of phosphatidylglycerol with lysine or alanine

tRNA ^His guanylyltransferase (THG1), a unique 3′-5′ nucleotidyl transferase, shares unexpected structural homology with canonical 5′-3′ DNA polymerases

Kinetic Partitioning between Synthetic and Editing Pathways in Class I Aminoacyl-tRNA Synthetases Occurs at Both Pre-transfer and Post-transfer Hydrolytic Steps

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Aminoacyl-tRNA synthetases: Versatile players in the changing theater of translation

Cited by 80 publications

References 82 publications

Structures of two bacterial resistance factors mediating tRNA-dependent aminoacylation of phosphatidylglycerol with lysine or alanine

Structures of two bacterial resistance factors mediating tRNA-dependent aminoacylation of phosphatidylglycerol with lysine or alanine

tRNA His guanylyltransferase (THG1), a unique 3′-5′ nucleotidyl transferase, shares unexpected structural homology with canonical 5′-3′ DNA polymerases

Kinetic Partitioning between Synthetic and Editing Pathways in Class I Aminoacyl-tRNA Synthetases Occurs at Both Pre-transfer and Post-transfer Hydrolytic Steps

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tRNA ^His guanylyltransferase (THG1), a unique 3′-5′ nucleotidyl transferase, shares unexpected structural homology with canonical 5′-3′ DNA polymerases