Department of Microbiology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia.
Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia.
Int J Mol Sci. 2022 Apr 4;23(7):4008. doi: 10.3390/ijms23074008.
Genomes of all organisms are persistently threatened by endogenous and exogenous assaults. Bacterial mechanisms of genome maintenance must provide protection throughout the physiologically distinct phases of the life cycle. Spore-forming bacteria must also maintain genome integrity within the dormant endospore. The nucleoid-associated proteins (NAPs) influence nucleoid organization and may alter DNA topology to protect DNA or to alter gene expression patterns. NAPs are characteristically multifunctional; nevertheless, Dps, HU and CbpA are most strongly associated with DNA protection. Archaea display great variety in genome organization and many inhabit extreme environments. As of yet, only MC1, an archaeal NAP, has been shown to protect DNA against thermal denaturation and radiolysis. ssDNA are intermediates in vital cellular processes, such as DNA replication and recombination. Single-stranded binding proteins (SSBs) prevent the formation of secondary structures but also protect the hypersensitive ssDNA against chemical and nuclease degradation. Ionizing radiation upregulates SSBs in the extremophile .
所有生物体的基因组都持续受到内源性和外源性攻击的威胁。细菌的基因组维护机制必须在生命周期的生理不同阶段提供保护。形成孢子的细菌还必须在休眠的芽孢内保持基因组完整性。核相关蛋白（NAPs）影响核小体的组织，可能改变 DNA 拓扑结构以保护 DNA 或改变基因表达模式。NAPs 通常具有多功能性；然而，Dps、HU 和 CbpA 与 DNA 保护的关系最为密切。古菌在基因组组织上表现出很大的多样性，并且许多古菌栖息在极端环境中。到目前为止，只有 MC1，一种古菌 NAP，被证明可以防止 DNA 热变性和放射分解。ssDNA 是 DNA 复制和重组等重要细胞过程的中间体。单链结合蛋白（SSBs）可以防止二级结构的形成，但也可以保护易感性 ssDNA 免受化学和核酸酶的降解。电离辐射会使极端微生物中的 SSBs 上调。
