Bacolla Albino, Wells Robert D
Center for Genome Research, Institute of Biosciences and Technology, Texas A&M University System Health Science Center, Texas Medical Center,2121 W. Holcombe Blvd.,Houston, TX 77030, USA.
Mol Carcinog. 2009 Apr;48(4):273-85. doi: 10.1002/mc.20507.
Repetitive DNA motifs may fold into non-B DNA structures, including cruciforms/hairpins, triplexes, slipped conformations, quadruplexes, and left-handed Z-DNA, thereby representing chromosomal targets for DNA repair, recombination, and aberrant DNA synthesis leading to repeat expansion or genomic rearrangements associated with neurodegenerative and genomic disorders. Hairpins and quadruplexes also determined the relative abundances of simple sequence repeats (SSR) in vertebrate genomes, whereas strong base stacking has permitted the expansion of purine.pyrimidine-rich SSR during evolutionary time. SSR are enriched in regulatory and cancer-related gene classes, where they have been actively recruited to participate in both gene and protein functions. SSR polymorphic alleles in the population are associated with cancer susceptibility, including within genes that appear to share regulatory circuits involving reactive oxygen species.
重复DNA基序可能折叠成非B型DNA结构，包括十字形/发夹结构、三链体、滑移构象、四链体和左手Z-DNA，因此代表了DNA修复、重组和异常DNA合成的染色体靶点，这些过程会导致重复序列扩增或与神经退行性疾病和基因组疾病相关的基因组重排。发夹结构和四链体还决定了脊椎动物基因组中简单序列重复（SSR）的相对丰度，而强大的碱基堆积作用使得富含嘌呤-嘧啶的SSR在进化过程中得以扩增。SSR在调控和癌症相关基因类别中富集，在这些基因中它们被积极招募以参与基因和蛋白质功能。群体中的SSR多态性等位基因与癌症易感性相关，包括在那些似乎共享涉及活性氧的调控回路的基因中。
