ニシヤマ　ソウイチロウ   Soichiro Nishiyama   西山　宗一郎    所属   新潟薬科大学  応用生命科学部 応用生命科学科    職種   准教授
言語種別	英語
発行・発表の年月	2018/06
形態種別	論文
査読	査読あり
標題	Dimerization site 2 of the bacterial DNA-binding protein H-NS is required for gene silencing and stiffened nucleoprotein filament formation.
執筆形態	共著
掲載誌名	The Journal of biological chemistry
掲載区分	国外
巻・号・頁	293(24),pp.9496-9505
著者・共著者	◎Yamanaka Yuki, Winardhi Ricksen S, Yamauchi Erika, Nishiyama So-ichiro, Sowa Yoshiyuki, Yan Jie, Kawagishi Ikuro, Ishihama Akira, Yamamoto Kaneyoshi
概要	The bacterial nucleoid-associated protein H-NS is a DNA-binding protein, playing a major role in gene regulation. To regulate transcription, H-NS silences genes, including horizontally acquired foreign genes. Escherichia coli H-NS is 137 residues long and consists of two discrete and independent structural domains: an N-terminal oligomerization domain and a C-terminal DNA-binding domain, joined by a flexible linker. Focusing on the function of dimerization site 2, we analyzed four variants, I70C/I70A and L75C/L75A, which all could actively bind DNA but are defective in gene silencing. Atomic force microscopy analysis of DNA-H-NS complexes revealed that all of these four variants formed condensed complexes on DNA. Single-molecule stretching experiments confirmed that the four variants had lost the ability to form stiffened filaments. We conclude that dimerization site 2 of H-NS plays a key role in the formation of rigid H-NS nucleoprotein filament structures required for gene silencing.
DOI	10.1074/jbc.RA117.001425
ISSN	1083-351X
PMID	29695505