Barstar is a small

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

synthesized by the bacterium '' Bacillus amyloliquefaciens''. Its function is to inhibit the

ribonuclease Ribonuclease (commonly abbreviated RNase) is a type of nuclease that catalyzes the degradation of RNA into smaller components. Ribonucleases can be divided into endoribonucleases and exoribonucleases, and comprise several sub-classes within th ...

activity of its binding partner barnase, with which it forms an extraordinarily tightly bound complex within the cell until barnase is secreted. Expression of barstar is necessary to counter the lethal effect of expressed active barnase. The structure of the barnase-barnstar complex is known.

References

Bacterial proteins {{protein-stub