Contents

08 March 2011
Vol 4, Issue 163

About The Cover

Cover image expansion

Online Cover This week features a Research Article that shows that monoubiquitination of Lys147 could enhance GTP loading on K-Ras and increase its affinity for specific downstream effectors, thus providing a previously unidentified mechanism for Ras activation. The accompanying Perspective provides context on the distinct effects of ubiquitination on the abundance, activity, and access to effectors of different Ras isoforms. The image, which is based on PDB structure 3GFT, shows the crystal structure of part of the guanine nucleotide–binding domain of K-Ras with Lys147 highlighted in red, bound to GDP (space-filling model). [Image: Chris Bickel, AAAS]