Histidine tRNA from chicken mitochondria has an uncoded 5'-terminal guanylate residue.

Labbé, Diane; Lang, B. Franz; Desjardins, Paul; Morais, Réjean

doi:10.1016/s0021-9258(19)39899-0

Cited by 31 publications

(4 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It would appear that the requirement for specific aminoacylation by HisRS provides strong principal selective pressure to maintain the G−1 element. Notably, its presence in prokaryotes imposes additional special constraints on processing by RNase P ( , ), and its presence in eukaryotes requires the posttranscriptional action of a dedicated nucleotidyl transferase ( , ).…”

Section: Discussionmentioning

confidence: 99%

“…Interestingly, histidine tRNAs of prokaryotic origin pair G−1 with a cytosine (conforming to Watson−Crick rules), while eukaryotic tRNAs possess an adenosine at position 73 (). Genes of prokaryotic histidine tRNAs directly encode for the extra guanosine, while a posttranscriptional mechanism operates in eukaryotes to incorporate G−1 ( , ). The extra guanosine nucleotide imposes specialized requirements for processing of the tRNA His acceptor stem by RNase P ( , ).…”

mentioning

confidence: 99%

See 1 more Smart Citation

G−1:C73 Recognition by an Arginine Cluster in the Active Site of Escherichia coli Histidyl-tRNA Synthetase

et al. 2004

View full text Add to dashboard Cite

Aminoacylation of a transfer RNA (tRNA) by its cognate aminoacyl-tRNA synthetase relies upon the recognition of specific nucleotides as well as conformational features within the tRNA by the synthetase. In Escherichia coli, the aminoacylation of tRNA(His) by histidyl-tRNA synthetase (HisRS) is highly dependent upon the recognition of the unique G-1:C73 base pair and the 5'-monophosphate. This work investigates the RNA-protein interactions between the HisRS active site and these critical recognition elements. A homology model of the tRNA(His)-HisRS complex was generated and used to design site-specific mutants of possible G-1:C73 contacts. Aminoacylation assays were performed with these HisRS mutants and N-1:C73 tRNA(His) and microhelix(His) variants. Complete suppression of the negative effect of 5'-phosphate deletion by R123A HisRS, as well as the increased discrimination of Q118E HisRS against a 5'-triphosphate, suggests a possible interaction between the 5'-phosphate and active-site residues Arg123 and Gln118 in which these residues create a sterically and electrostatically favorable pocket for the binding of the negatively charged phosphate group. Additionally, a network of interactions appears likely between G-1 and Arg116, Arg123, and Gln118 because mutation of these residues significantly reduced the sensitivity of HisRS to changes at G-1. Our studies also support an interaction previously proposed between Gln118 and C73. Defining the RNA-protein interactions critical for efficient aminoacylation by E. coli HisRS helps to further characterize the active site of this enzyme and improves our understanding of how the unique identity elements in the acceptor stem of tRNA(His) confer specificity.

show abstract

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

G−1:C73 Recognition by an Arginine Cluster in the Active Site of Escherichia coli Histidyl-tRNA Synthetase

et al. 2004

View full text Add to dashboard Cite

show abstract

“…In chicken mitochondria, the presence of a 5′-triphosphorylated G −1 on tRNA His was inferred by the ability of the in vivo-isolated tRNA to be capped by the capping guanylyltransferase, which requires a free 5′-triphosphate. 23 A more complete investigation of the 5′phosphorylation status of Thg1 and TLP reaction products in vivo may provide important evidence for how these reactions are controlled in various members of the Thg1 enzyme superfamily.…”

Section: ■ Associated Contentmentioning

confidence: 99%

Saccharomyces cerevisiae Thg1 Uses 5′-Pyrophosphate Removal To Control Addition of Nucleotides to tRNA^His

Smith

Jackman

2014

Biochemistry

View full text Add to dashboard Cite

In eukaryotes, the tRNAHis guanylyltransferase (Thg1) catalyzes 3′–5′ addition of a single guanosine residue to the −1 position (G–1) of tRNAHis, across from a highly conserved adenosine at position 73 (A73). After addition of G–1, Thg1 removes pyrophosphate from the tRNA 5′-end, generating 5′-monophosphorylated G–1-containing tRNA. The presence of the 5′-monophosphorylated G–1 residue is important for recognition of tRNAHis by its cognate histidyl-tRNA synthetase. In addition to the single-G–1 addition reaction, Thg1 polymerizes multiple G residues to the 5′-end of tRNAHis variants. For 3′–5′ polymerization, Thg1 uses the 3′-end of the tRNAHis acceptor stem as a template. The mechanism of reverse polymerization is presumed to involve nucleophilic attack of the 3′-OH from each incoming NTP on the intact 5′-triphosphate created by the preceding nucleotide addition. The potential exists for competition between 5′-pyrophosphate removal and 3′–5′ polymerase reactions that could define the outcome of Thg1-catalyzed addition, yet the interplay between these competing reactions has not been investigated for any Thg1 enzyme. Here we establish transient kinetic assays to characterize the pyrophosphate removal versus nucleotide addition activities of yeast Thg1 with a set of tRNAHis substrates in which the identity of the N–1:N73 base pair was varied to mimic various products of the N–1 addition reaction catalyzed by Thg1. We demonstrate that retention of the 5′-triphosphate is correlated with efficient 3′–5′ reverse polymerization. A kinetic partitioning mechanism that acts to prevent addition of nucleotides beyond the −1 position with wild-type tRNAHis is proposed.

show abstract

“…While it is assumed that cappable 5′ ends represent bona fide initiation sites, exceptions have been reported in which bi-or triphosphate ends of transcripts are created in vivo as a result of processing events (27). Such exceptions justify the need for functional assays by means of in vitro or in vivo systems.…”

Section: The Site S1 Initiates In Vitro Transcription In a Heterologo...mentioning

confidence: 99%

A promoter element active in run-off transcription controls the expression of two cistrons of nad and rps genes in Nicotiana sylvestris mitochondria

Lelandais

Gutierres

Mathieu

et al. 1996

Nucleic Acids Research

View full text Add to dashboard Cite

The expression of two mitochondrial gene clusters (orf87-nad3-nad1/A and orf87-nad3-rps12) was studied in Nicotiana sylvestris. 5' and 3' termini of transcripts were mapped by primer extension and nuclease S1 protection. Processing and transcription initiation sites were differentiated by in vitro phosphorylation and capping experiments. A transcription initiation site, present in both gene clusters, was found 213 nucleotides upstream of orf87. This promoter element matches the consensus motif for dicotyledonous mitochondrial promoters and initiates run-off transcription in a pea mitochondrial purified protein fraction. Processing sites were identified 5' of nad3, nad1/A and rps12 respectively. These results suggest that (i) the expression of the two cistrons is only controlled by one duplicated promoter element, and (ii) multiple processing events are required to produce monocistronic nad3, nad1/A and rps12 transcripts.

show abstract

Histidine tRNA from chicken mitochondria has an uncoded 5'-terminal guanylate residue.

Cited by 31 publications

References 28 publications

G−1:C73 Recognition by an Arginine Cluster in the Active Site of Escherichia coli Histidyl-tRNA Synthetase

G−1:C73 Recognition by an Arginine Cluster in the Active Site of Escherichia coli Histidyl-tRNA Synthetase

Saccharomyces cerevisiae Thg1 Uses 5′-Pyrophosphate Removal To Control Addition of Nucleotides to tRNA^His

A promoter element active in run-off transcription controls the expression of two cistrons of nad and rps genes in Nicotiana sylvestris mitochondria

Contact Info

Product

Resources

About

Histidine tRNA from chicken mitochondria has an uncoded 5'-terminal guanylate residue.

Cited by 31 publications

References 28 publications

G−1:C73 Recognition by an Arginine Cluster in the Active Site of Escherichia coli Histidyl-tRNA Synthetase

G−1:C73 Recognition by an Arginine Cluster in the Active Site of Escherichia coli Histidyl-tRNA Synthetase

Saccharomyces cerevisiae Thg1 Uses 5′-Pyrophosphate Removal To Control Addition of Nucleotides to tRNAHis

A promoter element active in run-off transcription controls the expression of two cistrons of nad and rps genes in Nicotiana sylvestris mitochondria

Contact Info

Product

Resources

About

Saccharomyces cerevisiae Thg1 Uses 5′-Pyrophosphate Removal To Control Addition of Nucleotides to tRNA^His