Mixed Anhydrides of Nucleotides and Amino Acids Give Dipeptides: A Model System for Studying the Origin of the Genetic Code?

2018 ◽  
Vol 3 (27) ◽  
pp. 7849-7855 ◽  
Author(s):  
Tao Wang ◽  
Pengbo Zhang ◽  
Gaobo Hu ◽  
Yuzhen Gao ◽  
Yile Wu ◽  
...  
Keyword(s):  
Amino Acids ◽  
Genetic Code ◽  
Model System ◽  
Mixed Anhydrides

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.

scholarly journals Sir3p Domains Involved in the Initiation of Telomeric Silencing in Saccharomyces cerevisiae

Genetics ◽  
1998 ◽  
Vol 150 (3) ◽  
pp. 977-986 ◽  
Author(s):  
Yangsuk Park ◽  
John Hanish ◽  
Arthur J Lustig
Keyword(s):  
Amino Acids ◽  
Active Site ◽  
Fusion Proteins ◽  
Initiation Site ◽  
Negative Control ◽  
Model System ◽  
Mutant Protein ◽  
Regulatory Domain ◽  
C Terminus ◽  
Necessary And Sufficient

Abstract Previous studies from our laboratory have demonstrated that tethering of Sir3p at the subtelomeric/telomeric junction restores silencing in strains containing Rap1-17p, a mutant protein unable to recruit Sir3p. This tethered silencing assay serves as a model system for the early events that follow recruitment of silencing factors, a process we term initiation. A series of LexA fusion proteins in-frame with various Sir3p fragments were constructed and tested for their ability to support tethered silencing. Interestingly, a region comprising only the C-terminal 144 amino acids, termed the C-terminal domain (CTD), is both necessary and sufficient for restoration of silencing. Curiously, the LexA-Sir3N205 mutant protein overcomes the requirement for the CTD, possibly by unmasking a cryptic initiation site. A second domain spanning amino acids 481-835, termed the nonessential for initiation domain (NID), is dispensable for the Sir3p function in initiation, but is required for the recruitment of the Sir4p C terminus. In addition, in the absence of the N-terminal 481 amino acids, the NID negatively influences CTD activity. This suggests the presence of a third region, consisting of the N-terminal half (1-481) of Sir3p, termed the positive regulatory domain (PRD), which is required to initiate silencing in the presence of the NID. These data suggest that the CTD “active” site is under both positive and negative control mediated by multiple Sir3p domains.

scholarly journals A Study of the Dynamic Interaction of Surfactants with Graphite and Carbon Nanotubes using Fmoc−Amino Acids as a Model System

Langmuir ◽  
2009 ◽  
Vol 25 (19) ◽  
pp. 11760-11767 ◽  
Author(s):  
Yanning Li ◽  
Brian G. Cousins ◽  
Rein V. Ulijn ◽  
Ian A. Kinloch
Keyword(s):  
Carbon Nanotubes ◽  
Amino Acids ◽  
Dynamic Interaction ◽  
Model System

On the Optimization of the Physicochemical Distances between Amino Acids in the Evolution of the Genetic Code

1994 ◽  
Vol 168 (1) ◽  
pp. 43-51 ◽  
Author(s):  
Massimo Di Giulio ◽  
M.Rosaria Capobianco ◽  
Mario Medugno
Keyword(s):  
Amino Acids ◽  
Genetic Code
Sign in / Sign up

Export Citation Format

Share Document