Ribonuclease II Activity in a “Presumptive” Ribonuclease II-Deficient Mutant

Optical activity of cystine-containing proteins. II. Circular dichroism spectra of pancreatic ribonuclease A, ribonuclease S, and ribonuclease S-protein.

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 ...

Anionic polymers. II. Inhibition of ribonuclease.

The hydrolysis of ribonucleic acid or a number of pyrimidine nucleotide 3’-phosphate esters as catalyzed by pancreatic ribonuclease is generally regarded as occurring in a biphasic fashion, the first phase involving formation of nucleoside-2’, 3’-cyclic phosphates, whereas the second involves hydrolysis of the cyclic intermediate to 3’-nucleoside phosphoric acids (1). Reports of inhibition of R...

Mutants of Escherichia coli lacking endonuclease I, ribonuclease I, or ribonuclease II.

To isolate mutants of Escherichia coli K-12 lacking endonuclease I activity (end), a method has been developed which detects, by differential methyl green staining, undegraded deoxyribonucleic acid (DNA) in colonies previously incubated in toluene. This procedure allows isolation of mutant strains in which DNA degradation is reduced. For half of these strains, this defect has been correlated wi...

A circular dichroic study of cu(II)-ribonuclease complexes.

Construction and characterization of an absolute deletion mutant of Escherichia coli ribonuclease II.

The degradation of mRNA plays a central role in the control of protein synthesis. In Escherichia coli, the rnb gene encodes ribonuclease II (RNase II), one of the two main exonucleases involved in mRNA decay. We have constructed strain CMA201, in which the rnb promoter region and the gene were deleted from the chromosome and replaced by a tetr cassette. This is the first rnb absolute deletion m...