RNA metabolism is a critical but frequently overlooked control element affecting virtually every cellular process in bacteria. RNA processing and degradation is mediated by a suite of ribonucleases having distinct cleavage and substrate specificity. Here, we probe the role of two ribonucleases (RNase III and RNase J) in the emerging model system Streptomyces venezuelae. We show that each enzyme...

Replication of the hepadnavirus DNA genome is accomplished via reverse transcription of an intermediate, pregenomic RNA molecule. This process is likely to be carried out by a virally encoded, multifunctional polymerase which possesses DNA- and RNA-dependent DNA polymerase and RNase H activities. However, the nature of the product(s) of the polymerase gene predicted to mediate these functions i...

The absB locus of Streptomyces coelicolor encodes a homolog of bacterial RNase III. We cloned and overexpressed the absB gene product and purified a decahistidine-tagged version of the protein. We show here that AbsB is active against double-stranded RNA transcripts derived from synthetic DNAs but is inactive with single-stranded homopolymers. We thus designate the absB product RNase IIIS. Usin...

Human pancreatic ribonuclease (HP-RNase) has considerable promise as a therapeutic agent. Structure-function analyses of HP-RNase have been impeded by the difficulty of obtaining the enzyme from its host. Here, a gene encoding HP-RNase was designed, synthesized, and inserted into two expression vectors that then direct the production of HP-RNase in Saccharomyces cerevisiae (fused to either an u...

incompatibility in hazelnut (c. avellana l.) is the sporophytic type and under the control of a single s-locus with multiple alleles. compatibility of pollen-stigma in hazelnut is an important consideration in planning crosses in breeding program and in choosing pollinizers for orchard planting. in this study, fluorescence microscopy was used to determination of s-alleles and compatibility rela...

Gametophytic self-incompatibility (GSI) is controlled by a complex S locus containing the pistil determinant S-RNase and pollen determinant SFB/SLF. Tight linkage of the pistil and pollen determinants is necessary to guarantee the self-incompatibility (SI) function. However, multiple probable pollen determinants of apple and Japanese pear, SFBBs (S locus F-box brothers), exist in each S haploty...

Ribonucleoproteins (RNP) are involved in many essential processes in life. However, the roles of RNA and protein subunits in an RNP complex are often hard to dissect. In many RNP complexes, including the ribosome and the Group II introns, one main function of the protein subunits is to facilitate RNA folding. However, in other systems, the protein subunits may perform additional functions, and ...