title: Structural investigation into physiological DNA phosphorothioate modification.
abstract: DNA phosphorothioate (PT) modification, with sulfur replacing a nonbridging phosphate oxygen in a sequence and stereo specific manner, is a novel physiological variation in bacteria. But what effects on DNA properties PT modification has is still unclear. To address this, we prepared three double-stranded (ds) DNA decamers, d(CG(PX)GCCGCCGA) with its complementary strand d(TCGGCG(PX)GCCG) (where X = O or S, i.e., PT-free dsDNA, [Sp, Sp]-PT dsDNA or [Rp, Rp]-PT dsDNA) located in gene of Streptomyces lividans. Their melting temperature (Tm) measurement indicates that [Rp, Rp]-PT dsDNA is most unstable. Their electron transfer potential detection presents an order of anti-oxidation properties: Sp-PT DNA > Rp-PT DNA > PT-free DNA. Their NMR structures demonstrate that PT modification doesn't change their B-form conformation. The sulfur in [Rp, Rp]-PT dsDNA locates in the major groove, with steric effects on protons in the sugar close to modification sites, resulting in its unstability, and facilitating its selectively interactions with ScoMcrA. We thought that PT modification was dialectical to the bacteria. It protects the hosting bacteria by working as antioxidant against H2O2, and acts as a marker, directing restriction enzyme observed in other hosts, like ScoMcrA, to correctly cleave the PT modified DNA, so that bacteria cannot spread and survive.
authors.affiliation: State Key Laboratory of Bio-organic and Natural Product Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.
authors.forename: Wenxian
authors.initials: W
authors.lastname: Lan
authors.affiliation: State Key Laboratory of Bio-organic and Natural Product Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.
authors.forename: Zhongpei
authors.initials: Z
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Bio-organic and Natural Product Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.|Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 Xiqidao, Tianjin Airport Economic Area, Tianjin, 300308, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Shen
authors.affiliation: State Key Laboratory of Bio-organic and Natural Product Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.
authors.forename: Chunxi
authors.initials: C
authors.lastname: Wang
authors.affiliation: Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 2019 Jialuo Road, Shanghai, 201800, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Jiang
authors.affiliation: State key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics of Chinese Academy of Sciences, West No.30 Xiao Hong Shan, Wuhan 430071, China.
authors.forename: Huili
authors.initials: H
authors.lastname: Liu
authors.affiliation: Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 2019 Jialuo Road, Shanghai, 201800, China.
authors.forename: Dewu
authors.initials: D
authors.lastname: Long
authors.affiliation: State key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics of Chinese Academy of Sciences, West No.30 Xiao Hong Shan, Wuhan 430071, China.
authors.forename: Maili
authors.initials: M
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Bio-organic and Natural Product Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.
authors.forename: Chunyang
authors.initials: C
authors.lastname: Cao
mesh_terms: D004247:DNA / Q000737:chemistry*; D004583:Electrons; D009682:Magnetic Resonance Spectroscopy; D009690:Nucleic Acid Conformation; D010710:Phosphates / Q000737:chemistry* / Q000378:metabolism; D012996:Solutions
chemical_list: D010710:Phosphates; D012996:Solutions; D004247:DNA; C035638:thiophosphoric acid