scholarly journals Replication Protein A Unfolds G-Quadruplex Structures with Varying Degrees of Efficiency

2012 ◽  
Vol 116 (19) ◽  
pp. 5588-5594 ◽  
Author(s):  
Mohammad H. Qureshi ◽  
Sujay Ray ◽  
Abby L. Sewell ◽  
Soumitra Basu ◽  
Hamza Balci
Keyword(s):  
Protein A ◽  
Replication Protein A ◽  
Replication Protein ◽  
G Quadruplex

scholarly journals Stabilization of a G-Quadruplex from Unfolding by Replication Protein A Using Potassium and the Porphyrin TMPyP4

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Aishwarya Prakash ◽  
Fabien Kieken ◽  
Luis A. Marky ◽  
Gloria E. O. Borgstahl
Keyword(s):  
Dna Replication ◽  
Protein A ◽  
Thermal Stabilization ◽  
Replication Protein A ◽  
Replication Protein ◽  
Unique Problem ◽  
Ssdna Binding ◽  
Binding Domains ◽  
G Quadruplex ◽  
Stabilization Effect

Replication protein A (RPA) plays an essential role in DNA replication by binding and unfolding non-canonical single-stranded DNA (ssDNA) structures. Of the six RPA ssDNA binding domains (labeled A-F), RPA-CDE selectively binds a G-quadruplex forming sequence (5′-TAGGGGAAGGGTTGGAGTGGGTT-3′called Gq23). In K+, Gq23 forms a mixed parallel/antiparallel conformation, and in Na+Gq23 has a less stable (TMlowered by ∼20∘C), antiparallel conformation. Gq23 is intramolecular and 1D NMR confirms a stable G-quadruplex structure in K+. Full-length RPA and RPA-CDE-core can bind and unfold the Na+form of Gq23 very efficiently, but complete unfolding is not observed with the K+form. Studies with G-quadruplex ligands, indicate that TMPyP4 has a thermal stabilization effect on Gq23 in K+, and inhibits complete unfolding by RPA and RPA-CDE-core. Overall these data indicate that G-quadruplexes present a unique problem for RPA to unfold and ligands, such as TMPyP4, could possibly hinder DNA replication by blocking unfolding by RPA.

scholarly journals Interaction of Replication Protein-A with G-Quadruplex Structures

2012 ◽  
Vol 102 (3) ◽  
pp. 71a
Author(s):  
Sujay Ray ◽  
Mohammad Haroon Qureshi ◽  
Dominic Malcom ◽  
Ugur Celik ◽  
Hamza Balci
Keyword(s):  
Protein A ◽  
Replication Protein A ◽  
Replication Protein ◽  
G Quadruplex

scholarly journals Replication protein A plays multifaceted roles complementary to specialized helicases in processing G-quadruplex DNA

iScience ◽  
2021 ◽  
pp. 102493
Author(s):  
Yi-Ran Wang ◽  
Ting-Ting Guo ◽  
Ya-Ting Zheng ◽  
Chang-Wei Lai ◽  
Bo Sun ◽  
...  
Keyword(s):  
Protein A ◽  
Replication Protein A ◽  
Replication Protein ◽  
Quadruplex Dna ◽  
G Quadruplex

scholarly journals Identification of the DNA-Binding Domains of Human Replication Protein A That Recognize G-Quadruplex DNA

2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Aishwarya Prakash ◽  
Amarnath Natarajan ◽  
Luis A. Marky ◽  
Michel M. Ouellette ◽  
Gloria E. O. Borgstahl
Keyword(s):  
Dna Binding ◽  
Protein A ◽  
Replication Protein A ◽  
Replication Protein ◽  
Binding Studies ◽  
Quadruplex Dna ◽  
Ssdna Binding ◽  
Dna Binding Domains ◽  
Binding Domains ◽  
G Quadruplex

Replication protein A (RPA), a key player in DNA metabolism, has 6 single-stranded DNA-(ssDNA-) binding domains (DBDs) A-F. SELEX experiments with the DBDs-C, -D, and -E retrieve a 20-nt G-quadruplex forming sequence. Binding studies show that RPA-DE binds preferentially to the G-quadruplex DNA, a unique preference not observed with other RPA constructs. Circular dichroism experiments show that RPA-CDE-core can unfold the G-quadruplex while RPA-DE stabilizes it. Binding studies show that RPA-C binds pyrimidine- and purine-rich sequences similarly. This difference between RPA-C and RPA-DE binding was also indicated by the inability of RPA-CDE-core to unfold an oligonucleotide containing a TC-region 5′ to the G-quadruplex. Molecular modeling studies of RPA-DE and telomere-binding proteins Pot1 and Stn1 reveal structural similarities between the proteins and illuminate potential DNA-binding sites for RPA-DE and Stn1. These data indicate that DBDs of RPA have different ssDNA recognition properties.

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