Small Prokaryotic DNA-Binding Proteins Protect Genome Integrity throughout the Life Cycle

Abstract

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 Deinococcus radiodurans.

Novel prokaryotic system employing previously unknown nucleic acids-based receptors

“…Thus, some biological effects so far associated with the action of nucleases against bacterial biofilms and inhibition of bacterial adhesion, might actually stem from previously overlooked alterations to TezRs with subsequent loss of their receptive and regulatory function [ 64 , 133 ]. Our data might also shed the light on the role of nucleic acids identified on cell surfaces, which have been described in some organisms but their contribution to cell functioning remained poorly defined [ 134 – 137 ].…”

Molecular Link between DNA Damage Response and Microtubule Dynamics

“…In bacteria, DSB repair mostly relies on HR, which involves the action of bacterial recombinase protein RecA [121,122,124]. Interestingly, a number of bacteria have evolved additional DNA protection mechanisms provided by small bacterial DNA-binding proteins, namely, nucleoid-associated proteins (NAPs; e.g., HU, DNA-binding protein from starved cells (Dps)), small acid-soluble spore proteins (SAAPs), and single-stranded binding proteins (SSBs) [125][126][127][128][129][130][131][132][133][134]. These small DNA-binding proteins are able to protect bacterial genomic DNA by the formation of nonspecific protein-DNA complexes, which could be linked with efficient DNA damage repair.…”

Amyloid-like Hfq interaction with single-stranded DNA: involvement in recombination and replication inEscherichia coli

“…This could particularly be the case for A-rich sequences found throughout the E. coli genome and when pH decreases during host infection (Kenney, 2019;Tolstorukov et al, 2005). Furthermore, it https://doi.org/10.1017/qrd.2022.15 Published online by Cambridge University Press could prevent ssDNA chemical attack or be involved in removal of secondary structures that could impair ssDNA related processes (Molan & Zgur Bertok, 2022).…”