%0 Journal Article
%T AtTRB1每3 Mediates Structural Changes in AtPOT1b to Hold ssDNA
%A Amit Jaiswal
%J ISRN Structural Biology
%D 2014
%R 10.1155/2014/827201
%X POT from Arabidopsis thaliana is a member of shelterin complex and belongs to Telo_bind protein family. Three homologs are reported, namely, AtPOT1a, AtPOT1b, and AtPOT1c, where AtPOT1b is involved in genomic stability and chromosome end protection by providing necessary grip to G-rich region of telomeric DNA for telomerase assembly. Telomeric binding factors (TRB1每3) physically interact with POT with no known functionality. In this work attempt has been made to elucidate the reason behind the interaction by analyzing molecular docking interaction between AtPOT1b and AtTRB1每3, which yielded potential residues, which could play essential role in structural modification. 3 ns molecular simulation helped to look into structural stability and conformational dynamics portraying domain movements. AtTRB＊s interaction with AtPOT1b provoked structural changes in AtPOT1b, thereby increasing the affinity for single strand DNA (ssDNA) as compared to double strand DNA (dsDNA). Although the obtained results require experimental evidence they can act as a guide in tracing the functions in other organisms. The information provided in this paper would be helpful in understanding functions of TRB1每3 with respect to genomic stability. 1. Introduction Protection of telomere (POT1) is a single strand (ss) DNA binding protein which holds together the G-rich region of the telomeric sequence. To do such an intense job complexes of proteins have to join hands together. One such complex is shelterin which comprises of TRF1, TRF2, TIN2, TPP1, POT1, and RAP1 proteins. POT1 makes its presence in almost all eukaryotes being conserved by nature [1]. POT1 safeguards from rapid telomere loss and chromosome end fusion. Interruption of POT1 gene caused telomere recombination and severe DNA damage response [2]. Three POT1 homologs are identified in Arabidopsis, namely, POT1a, POT1b, and POT1c, where POT1a helps in telomere synthesis while POT1b is associated with chromosome end protection [3]. Baumann and Cech reported that POT1b directly binds with telomeric G-rich region in yeast [4]. However, POT1b of Arabidopsis does not follow aforementioned statement suggesting other proteins to be responsible for uniting the interaction with DNA [5]. Another group of SMH-like proteins (AtTRB1每3) binds specifically with telomeric DNA with unknown functionality [6]. Fascinatingly, physical association was also reported between AtPOT1b and AtTRB1每3 [7] which may be involved through Telo_bind domain [8, 9]. Thus AtTRB1-3 might be a key player in arbitrating structural modifications in AtPOT1b to
%U http://www.hindawi.com/journals/isrn.structural.biology/2014/827201/