scholarly journals Mutational analysis of active-site residues in theMycobacterium lepraeRecA intein, a LAGLIDADG homing endonuclease: Asp122and Asp193are crucial to the double-stranded DNA cleavage activity whereas Asp218is not

2009 ◽  
pp. NA-NA ◽  
Author(s):  
Pawan Singh ◽  
Pankaj Tripathi ◽  
K. Muniyappa
Keyword(s):  
Active Site ◽  
Dna Cleavage ◽  
Mutational Analysis ◽  
Homing Endonuclease ◽  
Active Site Residues ◽  
Cleavage Activity ◽  
Double Stranded Dna ◽  
Dna Cleavage Activity

scholarly journals A YoeB toxin cleaves both RNA and DNA

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Julia McGillick ◽  
Jessica R. Ames ◽  
Tamiko Murphy ◽  
Christina R. Bourne
Keyword(s):  
Dna Cleavage ◽  
Divalent Cations ◽  
Nuclease Activity ◽  
Dose Dependence ◽  
Cleavage Activity ◽  
Double Stranded Dna ◽  
Dna Cleavage Activity ◽  
Evolutionarily Conserved ◽  
Toxin Protein ◽  
Rna And Dna

AbstractType II toxin-antitoxin systems contain a toxin protein, which mediates diverse interactions within the bacterial cell when it is not bound by its cognate antitoxin protein. These toxins provide a rich source of evolutionarily-conserved tertiary folds that mediate diverse catalytic reactions. These properties make toxins of interest in biotechnology applications, and studies of the catalytic mechanisms continue to provide surprises. In the current work, our studies on a YoeB family toxin from Agrobacterium tumefaciens have revealed a conserved ribosome-independent non-specific nuclease activity. We have quantified the RNA and DNA cleavage activity, revealing they have essentially equivalent dose-dependence while differing in requirements for divalent cations and pH sensitivity. The DNA cleavage activity is as a nickase for any topology of double-stranded DNA, as well as cleaving single-stranded DNA. AtYoeB is able to bind to double-stranded DNA with mid-micromolar affinity. Comparison of the ribosome-dependent and -independent reactions demonstrates an approximate tenfold efficiency imparted by the ribosome. This demonstrates YoeB toxins can act as non-specific nucleases, cleaving both RNA and DNA, in the absence of being bound within the ribosome.

scholarly journals DNA Cleavage Activity of the V(D)J Recombination Protein RAG1 Is Autoregulated

2004 ◽  
Vol 24 (15) ◽  
pp. 6850-6860 ◽  
Author(s):  
Pallabi De ◽  
Mandy M. Peak ◽  
Karla K. Rodgers
Keyword(s):  
Dna Cleavage ◽  
Active Site Residues ◽  
Inhibitory Effects ◽  
Central Domain ◽  
Cleavage Activity ◽  
Dna Cleavage Activity ◽  
Recombination Protein ◽  
Cleavage Reactions ◽  
Hydrolysis Of ◽  
B And T Lymphocytes

ABSTRACT RAG1 and RAG2 catalyze the first DNA cleavage steps in V(D)J recombination. We demonstrate that the isolated central domain of RAG1 has inherent single-stranded (ss) DNA cleavage activity, which does not require, but is enhanced by, RAG2. The central domain, therefore, contains the active-site residues necessary to perform hydrolysis of the DNA phosphodiester backbone. Furthermore, the catalytic activity of this domain on ss DNA is abolished by addition of the C-terminal domain of RAG1. The inhibitory effects of this latter domain are suppressed on substrates containing double-stranded (ds) DNA. Together, the activities of the reconstituted domains on ss versus mixed ds-ss DNA approximate the activity of intact RAG1 in the presence of RAG2. We propose how the combined actions of the RAG1 domains may function in V(D)J recombination and also in aberrant cleavage reactions that may lead to genomic instability in B and T lymphocytes.

scholarly journals Important Role for Phylogenetically Invariant PP2Acα Active Site and C-Terminal Residues Revealed by Mutational Analysis in Saccharomyces cerevisiae

Genetics ◽  
2000 ◽  
Vol 156 (1) ◽  
pp. 21-29 ◽  
Author(s):  
David R H Evans ◽  
Brian A Hemmings
Keyword(s):  
Protein Interactions ◽  
Active Site ◽  
Protein Function ◽  
Mutational Analysis ◽  
Yeast Cells ◽  
Temperature Sensitive ◽  
Active Site Residues ◽  
Catalytic Function

Abstract PP2A is a central regulator of eukaryotic signal transduction. The human catalytic subunit PP2Acα functionally replaces the endogenous yeast enzyme, Pph22p, indicating a conservation of function in vivo. Therefore, yeast cells were employed to explore the role of invariant PP2Ac residues. The PP2Acα Y127N substitution abolished essential PP2Ac function in vivo and impaired catalysis severely in vitro, consistent with the prediction from structural studies that Tyr-127 mediates substrate binding and its side chain interacts with the key active site residues His-118 and Asp-88. The V159E substitution similarly impaired PP2Acα catalysis profoundly and may cause global disruption of the active site. Two conditional mutations in the yeast Pph22p protein, F232S and P240H, were found to cause temperature-sensitive impairment of PP2Ac catalytic function in vitro. Thus, the mitotic and cell lysis defects conferred by these mutations result from a loss of PP2Ac enzyme activity. Substitution of the PP2Acα C-terminal Tyr-307 residue by phenylalanine impaired protein function, whereas the Y307D and T304D substitutions abolished essential function in vivo. Nevertheless, Y307D did not reduce PP2Acα catalytic activity significantly in vitro, consistent with an important role for the C terminus in mediating essential protein-protein interactions. Our results identify key residues important for PP2Ac function and characterize new reagents for the study of PP2A in vivo.

DNA-cleavage activity of the iron(II) complex with optically active ligands, meta- and para-xylyl-linked N’,N’-dipyridylmethyl-cyclohexane-1,2-diamine

2021 ◽  
Vol 36 ◽  
pp. 127834
Author(s):  
Koichi Kato ◽  
Yoshimi Ichimaru ◽  
Yoshinori Okuno ◽  
Yoshihiro Yamaguchi ◽  
Wanchun Jin ◽  
...  
Keyword(s):  
Dna Cleavage ◽  
Optically Active ◽  
Cleavage Activity ◽  
Dna Cleavage Activity

scholarly journals Correction to Copper(II) Complexes of l-Arginine as Netropsin Mimics Showing DNA Cleavage Activity in Red Light

2019 ◽  
Vol 58 (19) ◽  
pp. 13502-13503
Author(s):  
Ashis K. Patra ◽  
Tuhin Bhowmick ◽  
Sovan Roy ◽  
Suryanarayanarao Ramakumar ◽  
Akhil R. Chakravarty
Keyword(s):  
Dna Cleavage ◽  
Red Light ◽  
Cleavage Activity ◽  
Dna Cleavage Activity

Cytotoxic copper (II) mixed ligand complexes: Crystal structure and DNA cleavage activity

2011 ◽  
Vol 46 (9) ◽  
pp. 4537-4547 ◽  
Author(s):  
Verasuntharam M. Manikandamathavan ◽  
Royapuram P. Parameswari ◽  
Thomas Weyhermüller ◽  
Hannah R. Vasanthi ◽  
Balachandran Unni Nair
Keyword(s):  
Crystal Structure ◽  
Dna Cleavage ◽  
Mixed Ligand ◽  
Mixed Ligand Complexes ◽  
Cleavage Activity ◽  
Dna Cleavage Activity

Extra Copper-mediated Enhancement of the DNA Cleavage Activity Supported with Wild-type Cu, Zn Superoxide Dismutase

2008 ◽  
Vol 26 (3) ◽  
pp. 564-570 ◽  
Author(s):  
Ruo-Yu ZHOU ◽  
Wei JIANG ◽  
Li-Na ZHANG ◽  
Li WANG ◽  
Chang-Lin LIU
Keyword(s):  
Superoxide Dismutase ◽  
Dna Cleavage ◽  
Wild Type ◽  
Cleavage Activity ◽  
Dna Cleavage Activity
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