Reviews & Analysis

Apoptosis occurs through precise cellular pathways, whereas necrosis is generally thought of as a nonspecific cellular response to external damage. However, identification of a chemical inhibitor of necrotic events suggests that specific molecular pathways can also trigger necrosis.

Retroviruses have a stretch of RNA that dimerizes during viral particle formation. A new study suggests that RNA flexibility in the monomeric form may facilitate dimerization or other RNA-dependent viral functions.

Prenylation represents a critical step in the biosynthesis of many natural products. A new study reveals how aromatic prenyltransferase enzymes tolerate diverse aromatic polyketides while still controlling the length of prenyl side chains.

Identification of endogenous glycan-binding ligands for cell-surface receptors has been difficult. Incorporation of a photoactive sialic acid analog into B-cell surface glycoproteins suggests that CD22 molecules may cluster by binding carbohydrate antigens on neighboring CD22 molecules.

Ribozymes are enzymes comprised of RNA that fold into three-dimensional structures and that catalyze chemical reactions central to all cells. A new study shows that ribozymes, like proteins, may use general acid catalysis as part of their catalytic toolkit.

ComX is a post-translationally modified peptide involved in quorum sensing in Bacillus subtilis. The structure of ComX has now been shown to contain a geranylated tryptophan with an unusual tricyclic architecture.

Nitric oxide signaling requires that the heme of soluble guanylate cyclase bind NO preferentially to O₂. Engineering of the enzyme's active site reveals a molecular basis for NO binding selectivity.

The fate of cells depends on a delicate balance of pro- and anti-apoptotic proteins. Small-molecule inhibitors of anti-apoptotic protein-protein interactions promote apoptosis in cancer cells.