scholarly journals Improved plant cytosine base editors with high editing activity, purity, and specificity

Author(s):  
Qiurong Ren ◽  
Simon Sretenovic ◽  
Guanqing Liu ◽  
Zhaohui Zhong ◽  
Jiaheng Wang ◽  
...  
Keyword(s):  
2012 ◽  
Vol 443 (2) ◽  
pp. 477-484 ◽  
Author(s):  
Min Tan ◽  
Wei Yan ◽  
Ru-Juan Liu ◽  
Meng Wang ◽  
Xin Chen ◽  
...  

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.


2002 ◽  
Vol 22 (19) ◽  
pp. 6726-6734 ◽  
Author(s):  
Tetsuya Miyamoto ◽  
Junichi Obokata ◽  
Masahiro Sugiura

ABSTRACT RNA editing in higher-plant chloroplasts involves C-to-U conversions at specific sites. Although in vivo analyses have been performed, little is known about the biochemical aspects of chloroplast editing reactions. Here we improved our original in vitro system and devised a procedure for preparing active chloroplast extracts not only from tobacco plants but also from pea plants. Using our tobacco in vitro system, cis-acting elements were defined for psbE and petB mRNAs. Distinct proteins were found to bind specifically to each cis-element, a 56-kDa protein to the psbE site and a 70-kDa species to the petB site. Pea chloroplasts lack the corresponding editing site in psbE since T is already present in the DNA. Parallel in vitro analyses with tobacco and pea extracts revealed that the pea plant has no editing activity for psbE mRNAs and lacks the 56-kDa protein, whereas petB mRNAs are edited and the 70-kDa protein is also present. Therefore, coevolution of an editing site and its cognate trans-factor was demonstrated biochemically in psbE mRNA editing between tobacco and pea plants.


2019 ◽  
Author(s):  
Shalom Hillel Roth ◽  
Erez Y. Levanon ◽  
Eli Eisenberg

Abstract Adenosine to inosine (A-to-I) RNA editing by the ADAR enzymes is a common RNA modification, preventing false activation of the innate immune system by endogenous dsRNAs. Methods for quantification of ADAR activity are sought after, due to an increasing interest in the role of ADARs in cancer and auto-immune disorders, as well as attempts to harness the ADAR enzymes for RNA engineering. Here we present the Alu Editing Index (AEI), a robust and simple-to-use computational tool devised for this purpose that produces a single number representing the global editing level from BAM files. The AEI tool is available at https://github.com/a2iEditing/RNAEditingIndexer


2019 ◽  
Vol 16 (11) ◽  
pp. 1131-1138 ◽  
Author(s):  
Shalom Hillel Roth ◽  
Erez Y. Levanon ◽  
Eli Eisenberg

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Liron Klipcan ◽  
Igal Finarov ◽  
Nina Moor ◽  
Mark G. Safro

Aminoacyl-tRNA synthetases (aaRSs) are a canonical set of enzymes that specifically attach corresponding amino acids to their cognate transfer RNAs in the cytoplasm, mitochondria, and nucleus. The aaRSs display great differences in primary sequence, subunit size, and quaternary structure. Existence of three types of phenylalanyl-tRNA synthetase (PheRS)—bacterial (αβ)2, eukaryotic/archaeal cytosolic (αβ)2, and mitochondrial α—is a prominent example of structural diversity within the aaRSs family. Although archaeal/eukaryotic and bacterial PheRSs share common topology of the core domains and the B3/B4 interface, where editing activity of heterotetrameric PheRSs is localized, the detailed investigation of the three-dimensional structures from three kingdoms revealed significant variations in the local design of their synthetic and editing sites. Moreover, as might be expected from structural data eubacterial, Thermus thermophilus and human cytoplasmic PheRSs acquire different patterns of tRNAPhe anticodon recognition.


2006 ◽  
Vol 281 (44) ◽  
pp. 33217-33225 ◽  
Author(s):  
Vrajesh A. Karkhanis ◽  
Michal T. Boniecki ◽  
Kiranmai Poruri ◽  
Susan A. Martinis

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