Histone-like nucleoid-structuring protein (H-NS), is one of twelve nucleoid-associated proteins (NAPs) whose main function is the organization of genetic material, including the regulation of gene expression via xenogeneic silencing. H-NS is characterized by an N-terminal domain (NTD) consisting of two dimerization sites, a linker region that is unstructured and a C-terminal domain (CTD) that is responsible for DNA-binding. Though it is a small protein (15 kDa), it provides essential nucleoid compaction and regulation of genes (mainly silencing) and is highly expressed, functioning as a dimer or multimer. Change in temperature causes H-NS to be dissociated from the DNA duplex, allowing for transcription by RNA polymerase, and in specific regions lead to pathogenic cascades in enterobacteria such as Escherichia coli and the four Shigella species. Structure H-NS has a specific topology that allows it to condense bacterial DNA into a superhelical structure based on evidence from X-ray crystallography. The condensed superhelical structure has implicated H-NS in gene repression caused by the formation of oligomers. These oligomers form due to dimerization of two sites in the N-terminal domain of H-NS. For example, in bacterial species like Salmonella typhimurium, the NTD of H-NS contains dimerization sites in helices alpha 1, alpha 2 and alpha 3. Alpha helices 3 and 4 are then responsible for creating the superhelical structure of H-NS-DNA interactions by head to head association (Figure 2). H-NS also contains an unstructured linker region, also known as a Q-linker. The C-Terminal domain, also known as the DNA Binding Domain (DBD), shows high affinity for regions in DNA that are rich in Adenine and Thymine and present in a hook-like motif in a minor groove. The base stacking present in this AT rich region of the DNA allows for minor widening of the minor groove that is preferential for binding. Common DBD's include AACTA and TACTA regions which can appear hundreds of times throughout the genome. Within these AT-rich regions, the minor groove has a width of 3.5 Å, which is preferential for H-NS binding. In E. coli, it was observed that H-NS restructures the genome into microdomains in vivo. While the bacterial genome is split into four different macrodomains including Ori and Ter (macrodomain of E. coli and Shigella spp. in which H-NS is encoded), it is thought that H-NS plays a role in the formation of these small 10 kb microdomains throughout the genome. Function A major function of H-NS is