The recA1 mutation is a single point mutation that replaces glycine 160 of the recA polypeptide with an aspartic acid residue. The mutant recA1 protein has a greatly reduced single-stranded DNA-dependent ATPase activity at pH 7.5 compared to the wild-type protein. Interestingly, the recA1 protein does exhibit a vigorous ATPase activity at pH 6.2. To explore the molecular basis of this pH effect...

Accurately modeling unpaired regions of RNA is important for predicting structure, dynamics, and thermodynamics of folded RNA. Comparisons between NMR data and molecular dynamics simulations provide a test of force fields used for modeling. Here, NMR spectroscopy, including NOESY, (1)H-(31)P HETCOR, DQF-COSY, and TOCSY, was used to determine conformational preferences for single-stranded GACC R...

Gel electrophoresis is the standard method to separate, identify and purify nucleic acids. SSCP detects single base changes by altered mobility of single-stranded segments electrophoresed through non-denaturing polyacrylamide gels. Herein, changes in electrophoretic mobilities due to single base substitutions were measured for single-stranded segments of lengths ranging from 333 to 547 nt. A 48...

Computer-based molecular modeling of single stranded polysaccharide chains is capable of a quantitative description of the polymer chain dimensions in dilute aqueous solution. The influence of glycosidic linkage position and stereochemistry on the local chain trajectory is now well understood. Some illustrative results of modeling of this sort are reported here. More recent efforts to understan...

Mitochondrial DNA (mtDNA) gene defects may play a role in the development of non-insulin dependent diabetes mellitus (NIDDM). In order to search for potentially diabetogenic mtDNA defects we have applied the technique of single stranded conformational polymorphism (SSCP) analysis to 124 patients with a history of NIDDM and 40 non-diabetic controls. No new heteroplasmic mutations were detected. ...

Materials and methods: In this study a total of 17 trophozoite samples, obtained either directly from stool samples or after excystation, or by duodenal aspiration, were used. A set of primers was chosen to amplify the different regions of triose phosphate isomerase (tpi) and a segment of the glutamate dehydrogenase (gdh) genes. A single-stranded conformational polymorphism technique was also u...

Debaprasad Giri, Sanjay Kumar and Yashwant Singh Department of Physics, Banaras Hindu University, Varanasi 221 005, India Centre for Theoretical Studies, IIT, Kharagpur 721 302, India (Dated: February 1, 2008) Abstract A model of self-avoiding walk with suitable constraints on self-attraction is developed to describe the conformational behaviour of a single stranded short DNA molecule that form...

A silver nanorod array has been used for the intrinsic SERS detection of microRNAs based on different binding affinities of ssRNA, thiolated ssDNA, and the RNA:DNA duplex, eliminating the need for a labelling step.

Voltage biased solid-state nanopores are used to detect and characterize individual single stranded DNA molecules of fixed micrometer length by operating a nanopore detector at pH values greater than approximately 11.6. The distribution of observed molecular event durations and blockade currents shows that a significant fraction of the events obey a rule of constant event charge deficit (ecd) i...