Gametophytic self-incompatibility in Rosaceae, Solanaceae, and Scrophulariaceae is controlled by the S locus, which consists of an S-RNase gene and an unidentified "pollen S" gene. An approximately 70-kb segment of the S locus of the rosaceous species almond, the S haplotype-specific region containing the S-RNase gene, was sequenced completely. This region was found to contain two pollen-expres...

Several specific modifications, both proteolytic and chemical, have been performed on RNase A. The ability of each of these RNase A derivatives to bind the human placental RNase inhibitor has been determined in competition binding assays. The interaction depends upon the native conformation of the enzyme. Loss of active site residues His-12 and His-119, along with auxiliary residues Lys-7, Phe-...

The development of constrained peptides for inhibition of protein-protein interactions is an emerging strategy in chemical biology and drug discovery. This manuscript introduces a versatile, rapid and reversible approach to constrain peptides in a bioactive helical conformation using BID and RNase S peptides as models. Dibromomaleimide is used to constrain BID and RNase S peptide sequence varia...

Plants requiring an insect pollinator often produce nectar as a reward for the pollinator's visitations. This rich secretion needs mechanisms to inhibit microbial growth. In Nicotiana spp. nectar, anti-microbial activity is due to the production of hydrogen peroxide. In a close relative, Petunia hybrida, limited production of hydrogen peroxide was found; yet petunia nectar still has anti-bacter...

Although S-locus RNases (S-RNases) determine the specificity of pollen rejection in self-incompatible (SI) solanaceous plants, they alone are not sufficient to cause S-allele-specific pollen rejection. To identify non-S-RNase sequences that are required for pollen rejection, a Nicotiana alata cDNA library was screened by differential hybridization. One clone, designated HT, hybridized strongly ...

Ribonuclease S (RNase-S) is a complex that consists of two proteolytic fragments of bovine pancreatic ribonuclease A (RNase-A): the S-peptide (residues 1-20) and S-protein (residues 21-124). We have refined the crystal structures of three RNase-S complexes. The first two contain the full-length 20-residue S-peptide and were studied at pHs of 4.75 and 5.5. The third one consists of a truncated f...

BACKGROUND Although several studies have confirmed the association of xenotropic murine leukemia virus-related virus (XMRV) and prostate cancer, this association is still controversial, as most studies did not detect XMRV in prostate tissue samples. Furthermore, some genetic and epidemiological studies have highlighted a role for RNase L polymorphisms, particularly R462Q, in the progression of ...

It has been proved that the gametophytic self-incompatibility (GSI), mainly exists in Rosaceae and Solanaceae, is controlled by S genes, which are two tightly linked genes located at highly polymorphic S-locus: the S-RNase for pistil specificity and the F-box gene (SFB/SLF) for pollen specificity, respectively. However, the roles of those genes in SI of peach are still a subject of extensive de...

Control over mRNA stability is an essential part of gene regulation that involves both endo- and exoribonucleases. RNase Y is a recently identified endoribonuclease in Gram-positive bacteria, and an RNase Y ortholog has been identified in Streptococcus pyogenes (group A streptococcus [GAS]). In this study, we used microarray and Northern blot analyses to determine the S. pyogenes mRNA half-life...

Four S-RNases (RNase associated with self-incompatibility) were purified from the styles of two apple cultivars (Malus domestica), a self-incompatible cv., Starking Delicious (SD), and a self-compatible cv., Megumi (MG). Each cultivar produced two S-RNases and their enzymatic properties such as specific activity, pH optimum, thermal stability, and molecular mass, were characterized. The four S-...