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 role of ribonucleases in the control of gene expression remains unknown in lactic acid bacteria. In the present work, we analysed the expression of the citP gene, which encodes the lactococcal citrate permease P, through the stability of the citQRP messenger in both Lactococcus lactis biovar diacetylactis (L. diacetylactis) and Escherichia coli. The chemical half-life for citQRP mRNA observ...

The maturation of 5S ribosomal RNA in low G+C Gram-positive bacteria is catalyzed by a highly conserved, approximately 190 residue, enzyme, called ribonuclease M5 (RNase M5). Sequence alignment had predicted that the N-terminal half of RNase M5 would consist of a Toprim domain, a protein fold found in type IA and type II topoisomerases, DnaG-like primases, OLD family nucleases and RecR proteins...

Analogs of the 2',5'-linked adenylate trimer diphosphate (pp5'A2'p5'A2'p5'A or 2-5A) containing 8-bromoadenosine in the first, second, third, first and third, or second and third nucleotide positions (from the 5' terminus) were synthesized and found to vary dramatically in their ability to bind to and activate the RNase L of mouse L cells. Whenever the 8-bromoadenosine residue was substituted f...

Precursor molecules of Escherichia coli wild type and mutant tyrosine tRNA’s contain at both their 5’ and 3’ termini extra nucleotides in addition to those of the mature tRNA molecule. The early steps of processing these precursor molecules must involve specific ribonuclease cleavage. We report the isolation from E. coli extracts of the specific endonucleolytic RNase which cleaves only a single...

Encoding ribonuclease H1 (RNase H1) degrades RNA hybridized to DNA, and its function is essential for mitochondrial DNA maintenance in the developing mouse. Here we define the role of RNase H1 in mitochondrial DNA replication. Analysis of replicating mitochondrial DNA in embryonic fibroblasts lacking RNase H1 reveals retention of three primers in the major noncoding region (NCR) and one at the ...