geoscience.net logo
+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Absence of minor groove monovalent cations in the crosslinked dodecamer C-G-C-G-A-A-T-T-C-G-C-G


, : Absence of minor groove monovalent cations in the crosslinked dodecamer C-G-C-G-A-A-T-T-C-G-C-G. Journal of Molecular Biology 292(3): 589-608

The structure of a crosslinked B-DNA dodecamer of sequence C-G-C-G-A-A-T-T-C-G-C-G has been solved to a resolution of 1.43 ANG. The dithiobis-propane crosslink, -CH2-CH2-CH2-S-S-CH2-CH2-CH2-, bridges N7 atoms of adenine bases 6 and 18 in the two central base-pairs within the major groove. The crosslink is sufficiently long that no bending is induced in the helix, which is essentially isostructural with the native unlinked dodecamer at 1.9. ANG. A constellation of solvent peaks tentatively fitted as a spermine molecule in that earlier analysis is now seen at higher resolution to be a well-defined octahedral magnesium hexahydrate complex in the major groove. One end of the duplex curves around that complex to produce a roll-bend near base-pairs 3-5, and an overall bend in helix axis, as has long been noted. Two other magnesium complexes connect the helices and help to knit the crystal lattice together. No evidence exists for partial sodium or potassium ion substitution for solvent water molecules within the minor groove spine of hydration, as had been suggested previously: not coordination geometry and environment, nor B values, nor calculated valence values, nor difference map analyses. Indeed, the very numbers that have been claimed in support of partial substitution by sodium or potassium ions are reproduced with the present crystals, which by chemical analysis contains only one trace sodium ion per 160 bp, and one potassium ion per 41 bp. In contrast, our crystals contain one Mg2+ per base-pair, meaning that phosphate group charge neutrality is accomplished by divalent cations, not monovalent ions. Three of these magnesium cations per duplex are localized and visible in the X-ray analysis, and nine are disordered and invisible. Hence although binding of monovalent cations within the minor groove of A-tracts on occasion may be a consequence of groove narrowing, it cannot be the cause of that narrowing. Cations, contrary to what has been claimed, are notin charge.

US$19.90

PMID: 10497024

DOI: 10.1006/jmbi.1999.3075


Other references

Zhou, X-Long.; Huang, L.; Cao, J., 2016: Embelin Reduces Systemic Inflammation and Ameliorates Organ Injuries in Septic Rats Through Downregulating STAT3 and NF-κB Pathways. Current evidence shows that the majority of the damage induced during sepsis is pursuant to induction and overproduction of endogenous cytokines. Embelin has been reported to suppress cytokine expressions in inflammatory disorders. The present stu...

Olshin, J.M.; Smigo, T.M., 1991: Contracting speech-language pathology services to Medicare providers. Asha 33(11): 10-11

Wolkenhauer, O.; Shibata, D.K.; Mesarović, M.D., 2011: A stem cell niche dominance theorem. Multilevelness is a defining characteristic of complex systems. For example, in the intestinal tissue the epithelial lining is organized into crypts that are maintained by a niche of stem cells. The behavior of the system 'as a whole' is...

McCormick, W.C.; Uomoto, J.; Young, H.; Graves, A.B.; Vitaliano, P.; Mortimer, J.A.; Edland, S.D.; Larson, E.B., 1996: Attitudes toward use of nursing homes and home care in older Japanese-Americans. A cohort of 1142 older Japanese Americans was identified to study preferences and attitudes regarding use of long-term care (nursing home or home care). Prospective cohort study. Older Japanese Americans in King County, Washington. Subjects were a...

Fiori, A.; Marigo, M.; Benciolini, P., 1963: Modified absorption-elution method Siracusa for ABO and MN grouping of blood-stains. Journal of Forensic Sciences 8(3): 419-45 Contd

Yin, X.; Zheng, F-Qiang.; Tang, W.; Zhu, Q-Qin.; Li, X-Dong.; Zhang, G-Min.; Liu, H-Ting.; Liu, B-Shen., 2014: Genetic structure of rice black-streaked dwarf virus populations in China. Rice black-streaked dwarf virus (RBSDV) is a double-stranded RNA (dsRNA) virus belonging to the genus Fijivirus in the family Reoviridae. The genome of RBSDV consists of ten dsRNA segments. Although RBSDV has caused significant economic losses to...

Sullivan, J.P.; Lavoué, Sébastien.; Arnegard, M.E.; Hopkins, C.D., 2004: AFLPs resolve phylogeny and reveal mitochondrial introgression within a species flock of African electric fish (Mormyroidea: Teleostei). Estimating species phylogeny from a single gene tree can be especially problematic for studies of species flocks in which diversification has been rapid. Here we compare a phylogenetic hypothesis derived from cytochrome b (cyt b) sequences with an...

Soutoul, J.H.; Pierre, F., 1985: The court on tubal sterilization in 1985. The gynaecologist and the surgeon undertake unknown risks because the law as far as sterilisation is concerned is poor in case history and for this reason more to be feared. There is, apart from Penal Code 309-310-316 on voluntary infliction of in...

Kacperska, E.; Seyfriedowa, H.; Zupańska, B., 1969: Studies on antigen I in different proliferative diseases of the hemopoietic system. Archivum Immunologiae et Therapiae Experimentalis 17(5): 602-604

Maldonado J.; Bermudez R.H.; Ramirez Ronda R.; Vera D., 1982: Comparison of in vitro bacterial activity of povidone iodine with hexachlorophene against hospitals pathogens. Abstracts of the Annual Meeting of the American Society for Microbiology 82: ABSTRACT L16