2033: Caenorhabditis elegans NONO‐1: Insights into DBHS protein structure, architecture and function
Gavin J. Knott, Mihwa Lee, Daniel M. Passon, Archa H. Fox, and Charles S. Bond
The Drosophila behaviour/human splicing (DBHS) protein family are something of an enigma. With reported roles as accessory factors in almost every step of nuclear gene regulation, establishing a coherent picture for their molecular function is complicated. Herein we provide a structural platform for investigating the broad array of annotated DBHS protein functions using a combination of bioinformatics and X‐ray crystallography. These insights will assist in future directed exploration of DBHS protein function.
1934: Aromatic residues in RNase T stack with nucleobases to guide the sequence‐specific recognition and cleavage of nucleic acids
Yulander Duh, Yu‐Yuan Hsiao, Chia‐Lung Li, Jason C. Huang, and Hanna S. Yuan
RNase T is an exonuclease digesting RNA and DNA in various cellular processes, including RNA maturation and DNA repair. RNase T uses aromatic residues to stack with the nucleobases located at 3′ end of a nucleic acid chain and digests nucleic acids in a structure‐ and sequence‐specific manner. Here it is shown that replacement of the aromatic residues stacking with the nucleobases with different types of aromatic residues can change the sequence‐specific cleavage activity of RNase T. This report thus provides the first evidence showing that the π–π stacking interactions between nucleobases and protein aromatic residues may guide the sequence‐specific activity for DNA and RNA enzymes.
1901: Structural and mechanistic insights on nitrate reductases
Catarina Coelho and Maria João Romão
Nitrate reductases (NR) are key enzymes in the metabolism of the nitrogen cycle where they reduce nitrate to nitrite. NR belong to the DMSO reductase of Mo containing enzymes and due to variable cell location, function and structure they have been divided into periplasmic (Nap), cytoplasmic (Nas) and membrane‐bound (Nar) NR. Since the elucidation of the first crystal structure of the monomeric NapA in 1999, other novel crystal structures have been solved and different reaction mechanisms proposed. The most recent advances on their structure and function have been summarized in this review, with emphasis to the mechanistic implications derived from the crystallographic data.
1912: An electron microscopy journey in the study of microtubule structure and dynamics
Eva Nogales
Our structural knowledge of microtubules, essential polymers for the life of eukaryotic cells, has come from three‐dimensional electron microscopy and has evolved with the progress of this technique: from the initial 3D reconstructions of stained tubulin assemblies, to the first atomic model of tubulin by electron crystallography of 2D sheets of protofilaments, to the constantly improving cryo‐EM reconstructions of frozen‐hydrated microtubules. Today, microtubules structure at atomic resolution are providing us with the mechanistic details underlying the critical process of dynamic instability, the interaction of microtubules with associated factors, and the effect on microtubule structure of anticancer agents targeting tubulin.
