Document Detail

Non-productive DNA damage binding by DNA glycosylase-like protein Mag2 from Schizosaccharomyces pombe.
MedLine Citation:
PMID:  23273506     Owner:  NLM     Status:  MEDLINE    
Schizosaccharomyces pombe contains two paralogous proteins, Mag1 and Mag2, related to the helix-hairpin-helix (HhH) superfamily of alkylpurine DNA glycosylases from yeast and bacteria. Phylogenetic analysis of related proteins from four Schizosaccharomyces and other fungal species shows that the Mag1/Mag2 duplication is unique to the genus Schizosaccharomyces and most likely occurred in its ancestor. Mag1 excises N3- and N7-alkylguanines and 1,N(6)-ethenoadenine from DNA, whereas Mag2 has been reported to have no detectible alkylpurine base excision activity despite high sequence and active site similarity to Mag1. To understand this discrepancy we determined the crystal structure of Mag2 bound to abasic DNA and compared it to our previously determined Mag1-DNA structure. In contrast to Mag1, Mag2 does not flip the abasic moiety into the active site or stabilize the DNA strand 5' to the lesion, suggesting that it is incapable of forming a catalytically competent protein-DNA complex. Subtle differences in Mag1 and Mag2 interactions with the DNA duplex illustrate how Mag2 can stall at damage sites without fully engaging the lesion. We tested our structural predictions by mutational analysis of base excision and found a single amino acid responsible at least in part for Mag2's lack of activity. Substitution of Mag2 Asp56, which caps the helix at the base of the DNA intercalation loop, with the corresponding serine residue in Mag1 endows Mag2 with ɛA excision activity comparable to Mag1. This work provides novel insight into the chemical and physical determinants by which the HhH glycosylases engage DNA in a catalytically productive manner.
Suraj Adhikary; Marilyn C Cato; Kriston L McGary; Antonis Rokas; Brandt F Eichman
Related Documents :
24225116 - Efficient cellular fractionation improves rna sequencing analysis of mature and nascent...
23943636 - Draw+sneakpeek: analysis workflow and quality metric management for dna-seq experiments.
23541956 - Slowing pcr ramp speed reduces chimera formation from environmental samples.
10753206 - Arsenite induces dna-protein crosslinks and cytokeratin expression in the wrl-68 human ...
12808296 - Suppression of lipid hydroperoxide-induced oxidative damage to cellular dna by esculetin.
20439996 - Mutant huntingtin impairs ku70-mediated dna repair.
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.     Date:  2012-12-28
Journal Detail:
Title:  DNA repair     Volume:  12     ISSN:  1568-7856     ISO Abbreviation:  DNA Repair (Amst.)     Publication Date:  2013 Mar 
Date Detail:
Created Date:  2013-03-04     Completed Date:  2013-08-07     Revised Date:  2014-05-07    
Medline Journal Info:
Nlm Unique ID:  101139138     Medline TA:  DNA Repair (Amst)     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  196-204     Citation Subset:  IM    
Copyright Information:
Copyright © 2012 Elsevier B.V. All rights reserved.
Data Bank Information
Bank Name/Acc. No.:
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Amino Acid Sequence
Apurinic Acid / chemistry,  genetics
Catalytic Domain
Crystallography, X-Ray
DNA Damage
DNA Glycosylases / chemistry*
DNA, Fungal / chemistry*,  genetics
Models, Molecular
Molecular Sequence Data
Nucleic Acid Conformation
Protein Binding
Protein Structure, Secondary
Schizosaccharomyces / enzymology*
Schizosaccharomyces pombe Proteins / chemistry*
Surface Properties
Grant Support
Reg. No./Substance:
0/DNA, Fungal; 0/Schizosaccharomyces pombe Proteins; 11002-22-5/Apurinic Acid; EC 3.2.2.-/DNA Glycosylases; EC 3.2.2.-/Mag2 protein, S pombe

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Reversal for heparins and new anticoagulant treatments.
Next Document:  Children with intellectual disabilities may be impaired in encoding and recollecting incidental info...