Specific regions of the polypeptide sequence of pancreatic ribonuclease have been altered by chemical modification and by limited proteolytic digestion in attempts to implicate specific covalent portions of the molecule in the structure and stabilization of the active center. Digestion of the native molecule with trypsin at elevated temperatures has been shown to remove portions of the chain wi...

The circular dichroism spectra of pancreatic ribonuclease A, RNase S, and RNase S-protein have been measured in the wave length interval 198 to 300 mp under various conditions. The circular dichroism spectra of RNase A and S are very similar, possibly identical, over this entire wave length interval at neutral pH. That of RNase S-protein is substantially different. It is shown that the portion ...

The double strand-specific endoRNase RNase III globally regulates the production of antibiotics by Streptomyces coelicolor. We have undertaken studies to determine whether the endoRNase activity of S. coelicolor RNase III or its RNA binding activity is responsible for its regulatory function. We show that an rnc null mutant of S. coelicolor M145 does not produce actinorhodin or undecylprodigios...

RNase P is the ribonucleoprotein enzyme that cleaves precursor sequences from the 5' ends of pre-tRNAs. In Bacteria, the RNA subunit is the catalytic moiety. Eucaryal and archaeal RNase P activities copurify with RNAs, which have not been shown to be catalytic. We report here the analysis of the RNase P RNA from the thermoacidophilic archaeon Sulfolobus acidocaldarius. The holoenzyme was highly...

The phototriggered unbinding of the intrinsically disordered S-peptide from RNase S complex is studied with help transient IR spectroscopy, covering a wide range time scales 100 ps to 10 ms. To that end, an azobenzene moiety has been linked in way its helicity disrupted by light, thereby initiating complete unbinding. full sequence events observed, starting unfolding helical structure on 20 ns ...

Ribonuclease P (RNase P) is an essential endoribonuclease for which the best-characterized function is processing the 5' leader of pre-tRNAs. Compared to bacterial RNase P, which contains a single small protein subunit and a large catalytic RNA subunit, eukaryotic nuclear RNase P is more complex, containing nine proteins and an RNA subunit in Saccharomyces cerevisiae. Consistent with this, nucl...

Salmonella typhimurium LT2 contains intervening sequences (IVSs) of 90-110 nt within all its 23S rRNA that are cleaved out by RNase III, resulting in rRNA fragmentation. In order to determine the functionality of 23S rRNA that contains unexcised IVSs, we constructed an S. typhimurium RNase III (rnc) deficient strain by transducing a mini-Tn10 (rnc-14::Tn10) from Escherichia coli K-12. The resul...

Ribonuclease P is an ancient enzyme that cleaves pre-tRNAs to generate mature 5' ends. It contains an essential RNA subunit in Bacteria, Archaea, and Eukarya, but the degree to which the RNA subunit relies on proteins to supplement catalysis is highly variable. The eukaryotic nuclear holoenzyme has recently been found to contain almost twenty times the protein content of the bacterial enzymes, ...