Structural and Functional Differences between Homologous Bacterial Ribonucleases.

Small cationic guanyl-preferring ribonucleases (RNases) produced by the species share a similar protein tertiary structure with a high degree of amino acid sequence conservation. However, they form dimers that differ in conformation and stability. Here, we have addressed the issues (1) whether the homologous RNases also have distinctions in catalytic activity towards different RNA substrates and interactions with the inhibitor protein barstar, and (2) whether these differences correlate with structural features of the proteins.

The Cytotoxicity of RNase-Derived Peptides.

Bacterial ribonuclease binase exhibits a cytotoxic effect on tumor cells possessing certain oncogenes. The aim of this study was to identify the structural parts of the binase molecule that exert cytotoxicity. Out of five designed peptides, the peptides representing the binase regions 21-50 and 74-94 have the highest cytotoxic potential toward human cervical HeLa and breast BT-20 and MCF-7 cancer cells.

Antitumour Activity of the Ribonuclease Binase from in the RLS Tumour Model Is Associated with the Reorganisation of the miRNA Network and Reversion of Cancer-Related Cascades to Normal Functioning.

The important role of miRNA in cell proliferation and differentiation has raised interest in exogenous ribonucleases (RNases) as tools to control tumour-associated intracellular and extracellular miRNAs. In this work, we evaluated the effects of the RNase binase from on small non-coding regulatory RNAs in the context of mouse RLS lymphosarcoma inhibition. In vitro binase exhibited cytotoxicity towards RLS cells via apoptosis induction through caspase-3/caspase-7 activation and decreased the levels of miR-21a, let-7g, miR-31 and miR-155.

Extracellular Ribonuclease from (Balifase), a New Member of the N1/T1 RNase Superfamily.

The N1/T1 RNase superfamily comprises enzymes with well-established antitumor effects, such as ribotoxins secreted by fungi, primarily by and species, and bacterial RNase secreted by (binase) and (barnase). RNase is regarded as an alternative to classical chemotherapeutic agents due to its selective cytotoxicity towards tumor cells. New RNase with a high degree of structural similarity with binase (73%) and barnase (74%) was isolated and purified from (balifase, calculated molecular weight 12421.