Unveiling the structural mechanism of a G-quadruplex pH-Driven switch
Biochimie. 2023 Aug 10:S0300-9084(23)00193-1. doi: 10.1016/j.biochi.2023.08.002. Online ahead of print.ABSTRACTThe human telomere oligonucleotide, d[TAGGG(TTAGGG)2TTAGG] (TAGGG), can adopt two distinct 2-G-quartet G-quadruplex structures at pH 7.0 and 5.0, referred to as the TD and KDH+ forms, respectively. By using a combination of NMR and computational techniques, we determined high-resolution structures of both forms, which revealed unique loop architectures, base triples, and base pairs that play a crucial role in the pH-driven structural transformation of TAGGG. Our study demonstrated that TAGGG represents a reversibl...
Source: Biochimie - August 12, 2023 Category: Biochemistry Authors: Petra Galer Baifan Wang Janez Plavec Primo ž Šket Source Type: research

Human DNA ligases I and III α as determinants of accuracy and efficiency of base excision DNA repair
Biochimie. 2023 Aug 10:S0300-9084(23)00198-0. doi: 10.1016/j.biochi.2023.08.007. Online ahead of print.ABSTRACTMammalian Base Excision Repair (BER) DNA ligases I and IIIα (LigI, LigIIIα) are major determinants of DNA repair fidelity, alongside with DNA polymerases. Here we compared activities of human LigI and LigIIIα on specific and nonspecific substrates representing intermediates of distinct BER sub-pathways. The enzymes differently discriminate mismatches in the nicked DNA, depending on their identity and position, but are both more selective against the 3'-end non-complementarity. LigIIIα is less active than LigI ...
Source: Biochimie - August 12, 2023 Category: Biochemistry Authors: Nina A Moor Inna A Vasil'eva Olga I Lavrik Source Type: research

Viral nanoparticles: Current advances in design and development
Biochimie. 2023 Aug 10:S0300-9084(23)00197-9. doi: 10.1016/j.biochi.2023.08.006. Online ahead of print.ABSTRACTViral nanoparticles (VNPs) are self-assembling, adaptable delivery systems for vaccines and other therapeutic agents used in a variety of biomedical applications. The potential of viruses to invade and infect various hosts and cells renders them suitable as potential nanocarriers, possessing distinct functional characteristics, immunogenic properties, and improved biocompatibility and biodegradability. VPNs are frequently produced through precise genetic or chemical engineering, which involves adding diverse seque...
Source: Biochimie - August 12, 2023 Category: Biochemistry Authors: Siva Santhiya Arul Brinda Balakrishnan Savithri S Handanahal Sangita Venkataraman Source Type: research

Unveiling the structural mechanism of a G-quadruplex pH-Driven switch
Biochimie. 2023 Aug 10:S0300-9084(23)00193-1. doi: 10.1016/j.biochi.2023.08.002. Online ahead of print.ABSTRACTThe human telomere oligonucleotide, d[TAGGG(TTAGGG)2TTAGG] (TAGGG), can adopt two distinct 2-G-quartet G-quadruplex structures at pH 7.0 and 5.0, referred to as the TD and KDH+ forms, respectively. By using a combination of NMR and computational techniques, we determined high-resolution structures of both forms, which revealed unique loop architectures, base triples, and base pairs that play a crucial role in the pH-driven structural transformation of TAGGG. Our study demonstrated that TAGGG represents a reversibl...
Source: Biochimie - August 12, 2023 Category: Biochemistry Authors: Petra Galer Baifan Wang Janez Plavec Primo ž Šket Source Type: research

Human DNA ligases I and III α as determinants of accuracy and efficiency of base excision DNA repair
Biochimie. 2023 Aug 10:S0300-9084(23)00198-0. doi: 10.1016/j.biochi.2023.08.007. Online ahead of print.ABSTRACTMammalian Base Excision Repair (BER) DNA ligases I and IIIα (LigI, LigIIIα) are major determinants of DNA repair fidelity, alongside with DNA polymerases. Here we compared activities of human LigI and LigIIIα on specific and nonspecific substrates representing intermediates of distinct BER sub-pathways. The enzymes differently discriminate mismatches in the nicked DNA, depending on their identity and position, but are both more selective against the 3'-end non-complementarity. LigIIIα is less active than LigI ...
Source: Biochimie - August 12, 2023 Category: Biochemistry Authors: Nina A Moor Inna A Vasil'eva Olga I Lavrik Source Type: research