S nuclease

DNase I stock solutions are stored at -2O C (1 mg/ml) in 5- xl aliquots (each aliquot is used once). Variation in the activity of DNase I preparations is often observed and the exact amount needed to introduce the desired number of nicks should be determined for each enzyme batch. Sometimes template switches occur which will result in snap-back structures (zero-binding nucleic acid), which remain S, nuclease-resistant upon denaturation. Rigby et al. (1977) suggested that this effect was due to a differential loss of 5 - 3 exonuclease activity upon storage leading to a displacement of the nicked strand and a template switch from the complementary... 

Fig. 17. Frequency-domain data for the intrinsic fluorescence of S] Nuclease and melittin.

Both melittin and S, Nuclease contain a single tryptophan residue. The data illustrated the point that the emission from such simple proteins can be multiexponential. Even though only a single residue is responsible for the emission, it was not possible to fit the data using a single decay time. This is shown by the failure of... 

The enzyme begins its exonucleolytic attack at the 5 terminus of DNA, liberating almost entirely 5 -dNMP (11). The 5 -exonuclease hydrolyzes 5 -phosphoryl-and 5 -OH-terminated DNA at equal rates (12). The enzyme releases a dinucleoside monophosphate from the 5 -OH terminus and NTP from the 5 -triphosphate terminus (13). In fact, the gene 6 nuclease has been shown, like the S nuclease of E. coli DNA Pol I, to function on model substrates as a structure-specific endonuclease (46). The gene 6 nuclease also degrades RNA in a variety of RNA DNA hybrids and thus has an RNase H activity. 

SNase, see Staphylococcal nuclease (SNase) S,v2 reactions, see Substitution reactions, nucleophilic (Sw2)... 

In this review, NMR analysis of the denatured state of staphylococcal nuclease is briefly reviewed in nontechnical language. Most of the work has come from the author s laboratory over the past eight years. The initial experiments, which only measure local structural parameters, reported small amounts of persisting helical structure, two turns, and indirect evidence for perhaps a three-strand beta meander. When applied to the denatured state in 6 M urea, the same experiments indicated that most of these features are lost. 

Godfrey TE, Kim S-H, Chavira M, et al. Quantitative mRNA expression analysis from formalin-fixed, paraffin-embedded tissues using 5 nuclease quantitative reverse transcription-polymerase chain reaction. J. Mol. Diagn. 2000 2 84-91. 

Linn, S.M. Roberts, R.J., Ed. "Nucleases , Cold Spring Harbor Laboratory Cold Spring Harbor, 1982. 

Dunn, B.M., and Affinsen, C.B. (1974) Kinetics of Woodward s reagent K hydrolysis and reaction with staphylococcal nuclease./. Biol. Chem. 249, 3717. 

The FastA results show that the sequence is 47% identical over the entire length to the mitochondrial nuclease from S. cerevisiae ... 

This example comes from Q10480, the PROBABLE MITOCHONDRIAL NUCLEASE of S. pombe, which was used as an example for a protein without biochemical characterization. The label by similarity indicates that this feature has been assigned owing to similarity to an existing characterized entry, in this case the mitochondrial nuclease from S. cerevisiae. 

Uversky, V.N., A.S. Kamoup, D.J. Segel, S. Seshadri, S. Doniach, and A.L. Fink. 1998. Anion-induced folding of Staphylococcal nuclease characterization of multiple equilibrium partially folded intermediates. J Mol Biol 278 879-894. 

To determine the binding sites of proteins on the rRNA different methods have been used, most notably enzymatic digestion of the rRNA around the protein that protects the RNA binding site from nuclease attack. Details and results of these studies have been reviewed (Zimmer-mann, 1980 Wittmann, 1982 Brimacombe et al., 1978, 1983). The binding sites so obtained vary in length from about 50 nucleotides for protein S8 to about 500 nucleotides for protein S4. The 5 region of the 16 S rRNA contains the sites for proteins S4, S12, and S20. The 3 ... 

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