Volume 9 Issue 12, December 2002

The structures of four lysine methyltransferases give us the first glimpse of the molecular architecture responsible for histone/protein lysine methylation, whereas a recent study of the Esa1 histone acetyltransferase suggests that lysine acetyltransferases still have surprises in store.

Proteins are the dogmatic workhorses of genetic regulation, able to both sense the presence of small molecules and control gene expression levels. Two recent studies have now shown that RNA molecules can also serve as the 'sensor' components of genetic regulatory circuits.

Histone methylation regulates the transcriptional activity of genes in the chromatin fiber and might provide a mechanistic basis for inheritable epigenetic patterns of gene transcription.

The crystal structure of the central region of Rad51 bound to a BRC peptide from BRCA2 shows that the BRC peptide mimics a structural motif within Rad51 and can thereby regulate assembly of the Rad51 nucleoprotein filament needed for DNA repair.