Researchers have mapped the physicochemical properties of proteins in 20,000 organisms. The results, published in The Proceedings of the National Academy of Sciences (PNAS), show that the properties not only provide clues to understanding evolution and adaptation, but also add new dimensions to the established taxonomical classification system.
Ribonucleotide reductase (RNR) is an essential enzyme that catalyzes the synthesis of DNA building blocks. In a new study from Britt-Marie Sjöberg’s and Pål Stenmark’s groups at DBB, they present several cryo-EM structures and the mechanism of action of NrdR. NrdR is the RNR-specific repressor, that controls transcription of RNR genes in bacteria. The repressor uses an unprecedented nucleotide-sensing oligomerization mechanism to control NrdR-dependent transcription of ribonucleotide reductases.