tailieunhanh - Báo cáo khoa học: DNA G-quadruplex: structure, function and human disease ´ ´ Jaime Gomez-Marquez

Tham khảo luận văn - đề án 'báo cáo khoa học: dna g-quadruplex: structure, function and human disease ´ ´ jaime gomez-marquez', luận văn - báo cáo, báo cáo khoa học phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | ỊFEBS Journal MINIREVIEW SERIES DNA G-quadruplex structure function and human disease Jaime Gomez-Marquez Department of Biochemistry and Molecular Biology Faculty of Biology-CIBUS University of Santiago de Compostela USC Spain The role of non-B DNA in the function and stability of genomes has become generally appreciated in recent years. It is now evident that DNA also encodes for spatial structures that are involved in gene regulation replication and recombination. There are several types of secondary structures in non-B DNA. Among these noncanonical structures are hairpins and cruciforms intramolecular triplexes or H-DNA left-handed Z-DNA and guanine-rich repeats which have the capacity to adopt G-quadruplex G4-DNA the latter structure is also referred to in the literature as G-tetraplex. G4-DNA consists of a hydrogen-bonded self-assembly of four guanine bases paired by Hoogsteen bonding which forms planar arrangements the G-quartets. Charge coordination by monovalent cations stabilizes G-quartet stacking resulting in intramolecular or intermolecular association of four DNA strands in a parallel or antiparallel orientation. Genomes contain a high number of G-rich sequences that could form G4-DNA and this structure may serve important regulatory and structural functions in addition it can be the source of genomic instability which may lead to cancer aging and human genetic diseases. In silico analysis using different computational methods as well as laboratory experiments indicates that many G-rich regions of chromosomes - rDNA single-copy genes recombination sites like those involved in immunoglobulin class-switching and repetitive sequences including satellite and telomeric DNA sequences - have the potential to form G4-DNA structures. Interestingly RNA is also capable of forming G4 structures even more stable than those of DNA. In this sense it is tempting to speculate that RNA G-quadru-plexes could play a role in translation regulation in a manner analogous to