scholarly journals Pyrrolysyl-tRNA Synthetase with a Unique Architecture Enhances the Availability of Lysine Derivatives in Synthetic Genetic Codes

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2460 ◽  
Author(s):  
Atsushi Yamaguchi ◽  
Fumie Iraha ◽  
Kazumasa Ohtake ◽  
Kensaku Sakamoto
Keyword(s):  
Amino Acid ◽  
Binding Pocket ◽  
Trna Synthetase ◽  
Aminoacyl Trna Synthetase ◽  
Genetic Codes ◽  
Genetic Code Expansion ◽  
Amino Acid Binding ◽  
Derivatives Of ◽  
Additional Nucleotide ◽  
Incorporation Efficiency

Genetic code expansion has largely relied on two types of the tRNA—aminoacyl-tRNA synthetase pairs. One involves pyrrolysyl-tRNA synthetase (PylRS), which is used to incorporate various lysine derivatives into proteins. The widely used PylRS from Methanosarcinaceae comprises two distinct domains while the bacterial molecules consist of two separate polypeptides. The recently identified PylRS from Candidatus Methanomethylophilus alvus (CMaPylRS) is a single-domain, one-polypeptide enzyme that belongs to a third category. In the present study, we showed that the PylRS—tRNAPyl pair from C. M. alvus can incorporate lysine derivatives much more efficiently (up to 14-times) than Methanosarcinaceae PylRSs in Escherichia coli cell-based and cell-free systems. Then we investigated the tRNA and amino-acid recognition by CMaPylRS. The cognate tRNAPyl has two structural idiosyncrasies: no connecting nucleotide between the acceptor and D stems and an additional nucleotide in the anticodon stem and it was found that these features are hardly recognized by CMaPylRS. Lastly, the Tyr126Ala and Met129Leu substitutions at the amino-acid binding pocket were shown to allow CMaPylRS to recognize various derivatives of the bulky Nε-benzyloxycarbonyl-l-lysine (ZLys). With the high incorporation efficiency and the amenability to engineering, CMaPylRS would enhance the availability of lysine derivatives in expanded codes.

scholarly journals Transferability of N-terminal mutations of pyrrolysyl-tRNA synthetase in one species to that in another species on unnatural amino acid incorporation efficiency

Amino Acids ◽  
2020 ◽  
Author(s):  
Thomas L. Williams ◽  
Debra J. Iskandar ◽  
Alexander R. Nödling ◽  
Yurong Tan ◽  
Louis Y. P. Luk ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Genetic Code ◽  
Unnatural Amino Acids ◽  
Trna Synthetase ◽  
Unnatural Amino Acid ◽  
Amino Acid Incorporation ◽  
Acid Incorporation ◽  
Genetic Code Expansion ◽  
Incorporation Efficiency

AbstractGenetic code expansion is a powerful technique for site-specific incorporation of an unnatural amino acid into a protein of interest. This technique relies on an orthogonal aminoacyl-tRNA synthetase/tRNA pair and has enabled incorporation of over 100 different unnatural amino acids into ribosomally synthesized proteins in cells. Pyrrolysyl-tRNA synthetase (PylRS) and its cognate tRNA from Methanosarcina species are arguably the most widely used orthogonal pair. Here, we investigated whether beneficial effect in unnatural amino acid incorporation caused by N-terminal mutations in PylRS of one species is transferable to PylRS of another species. It was shown that conserved mutations on the N-terminal domain of MmPylRS improved the unnatural amino acid incorporation efficiency up to five folds. As MbPylRS shares high sequence identity to MmPylRS, and the two homologs are often used interchangeably, we examined incorporation of five unnatural amino acids by four MbPylRS variants at two temperatures. Our results indicate that the beneficial N-terminal mutations in MmPylRS did not improve unnatural amino acid incorporation efficiency by MbPylRS. Knowledge from this work contributes to our understanding of PylRS homologs which are needed to improve the technique of genetic code expansion in the future.

The zinc-binding site of a class I aminoacyl-tRNA synthetase is a SWIM domain that modulates amino acid binding via the tRNA acceptor arm

2004 ◽  
Vol 271 (4) ◽  
pp. 724-733 ◽  
Author(s):  
Rajat Banerjee ◽  
Daniel Y. Dubois ◽  
Joelle Gauthier ◽  
Sheng-Xiang Lin ◽  
Siddhartha Roy ◽  
...  
Keyword(s):  
Amino Acid ◽  
Binding Site ◽  
Trna Synthetase ◽  
Class I ◽  
Zinc Binding ◽  
Aminoacyl Trna Synthetase ◽  
Zinc Binding Site ◽  
Amino Acid Binding ◽  
Trna Acceptor

Structural Basis of Furan-Amino Acid Recognition by a Polyspecific Aminoacyl-tRNA-Synthetase and its Genetic Encoding in Human Cells

ChemBioChem ◽  
2014 ◽  
Vol 15 (12) ◽  
pp. 1755-1760 ◽  
Author(s):  
Moritz J. Schmidt ◽  
Annemarie Weber ◽  
Moritz Pott ◽  
Wolfram Welte ◽  
Daniel Summerer
Keyword(s):  
Amino Acid ◽  
Trna Synthetase ◽  
Human Cells ◽  
Structural Basis ◽  
Aminoacyl Trna Synthetase ◽  
Genetic Encoding ◽  
Amino Acid Recognition

scholarly journals Translational switching of Cry1 protein expression confers reversible control of circadian behavior in arrhythmic Cry-deficient mice

2018 ◽  
Vol 115 (52) ◽  
pp. E12388-E12397 ◽  
Author(s):  
Elizabeth S. Maywood ◽  
Thomas S. Elliott ◽  
Andrew P. Patton ◽  
Toke P. Krogager ◽  
Johanna E. Chesham ◽  
...  
Keyword(s):  
Stop Codon ◽  
Trna Synthetase ◽  
Aminoacyl Trna Synthetase ◽  
Adeno Associated Virus ◽  
Biologically Relevant ◽  
Negative Feedback Loops ◽  
Translational Readthrough ◽  
Genetic Code Expansion ◽  
And Behavior ◽  
Circadian Behavior

The suprachiasmatic nucleus (SCN) is the principal circadian clock of mammals, coordinating daily rhythms of physiology and behavior. Circadian timing pivots around self-sustaining transcriptional–translational negative feedback loops (TTFLs), whereby CLOCK and BMAL1 drive the expression of the negative regulators Period and Cryptochrome (Cry). Global deletion of Cry1 and Cry2 disables the TTFL, resulting in arrhythmicity in downstream behaviors. We used this highly tractable biology to further develop genetic code expansion (GCE) as a translational switch to achieve reversible control of a biologically relevant protein, Cry1, in the SCN. This employed an orthogonal aminoacyl-tRNA synthetase/tRNACUA pair delivered to the SCN by adeno-associated virus (AAV) vectors, allowing incorporation of a noncanonical amino acid (ncAA) into AAV-encoded Cry1 protein carrying an ectopic amber stop codon. Thus, translational readthrough and Cry1 expression were conditional on the supply of ncAA via culture medium or drinking water and were restricted to neurons by synapsin-dependent expression of aminoacyl tRNA-synthetase. Activation of Cry1 translation by ncAA in neurons of arrhythmic Cry-null SCN slices immediately and dose-dependently initiated TTFL circadian rhythms, which dissipated rapidly after ncAA withdrawal. Moreover, genetic activation of the TTFL in SCN neurons rapidly and reversibly initiated circadian behavior in otherwise arrhythmic Cry-null mice, with rhythm amplitude being determined by the number of transduced SCN neurons. Thus, Cry1 does not specify the development of circadian circuitry and competence but is essential for its labile and rapidly reversible activation. This demonstrates reversible control of mammalian behavior using GCE-based translational switching, a method of potentially broad neurobiological interest.

scholarly journals Transcription and translation in an RNA world

2006 ◽  
Vol 361 (1474) ◽  
pp. 1751-1760 ◽  
Author(s):  
William R Taylor
Keyword(s):  
Amino Acid ◽  
Active Site ◽  
Rna World ◽  
Large Subunit ◽  
Trna Synthetase ◽  
Nucleoside Triphosphate ◽  
Amino Acid Binding ◽  
World Hypothesis ◽  
Protein Elongation ◽  
Rna World Hypothesis

The RNA world hypothesis requires a ribozyme that was an RNA-directed RNA polymerase (ribopolymerase). If such a replicase makes a reverse complementary copy of any sequence (including itself), in a simple RNA world, there is no mechanism to prevent self-hybridization. It is proposed that this can be avoided through the synthesis of a parallel complementary copy. The logical consequences of this are pursued and developed in a computer simulation, where the behaviour of the parallel copy is compared to the conventional reverse complementary copy. It is found that the parallel copy is more efficient at higher temperatures (up to 90°C). A model for the ribopolymerase, based on the core of the large subunit (LSU) of the ribosome, is described. The geometry of a potential active site for this ribopolymerase suggests that it contained a cavity (now occupied by the aminoacyl-tRNA) and that an amino acid binding in this might have ‘poisoned’ the ribopolymerase by cross-reacting with the nucleoside-triphosphate before polymerization could occur. Based on a similarity to the active site components of the class-I tRNA synthetase enzymes, it is proposed that the amino acid could become attached to the nascent RNA transcript producing a variety of aminoacylated tRNA-like products. Using base-pairing interactions, some of these molecules might cross-link two ribopolymerases, giving rise to a precursor of the modern ribosome. A hybrid dimer, half polymerase and half proto-ribosome, could account for mRNA translocation before the advent of protein elongation factors.

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