• Twinfilin binds CP via TWtail that has sequence similarity to CARMIL CPI. Here we present the crystal structure of in complex with TWtail. and CPI restrict distinct conformations. Unlike CPI, forms a stable ternary V-1. Our data suggest acts cooperatively V-1 destabilize F-actin. is conserved actin regulator interacts capping protein (CP) C terminus residues (TWtail) exhibits interaction (CPI...

The fluctuations of three-dimensional molecular conformations of a molecule in different environments play critical roles in many important chemical and biological processes. X-ray diffraction (XRD) techniques and nuclear magnetic resonance (NMR) methods are routinely applied to monitor the molecular conformations in condensed phases. However, some special requirements of the methods have preve...

We investigate the role of steric interactions in defining side-chain conformations in protein cores. Previously, we explored the strengths and limitations of hard-sphere dipeptide models in defining sterically allowed side-chain conformations and recapitulating key features of the side-chain dihedral angle distributions observed in high-resolution protein structures. Here, we show that modelin...

ClpX, a AAA+ ring homohexamer, uses the energy of ATP binding and hydrolysis to power conformational changes that unfold and translocate target proteins into the ClpP peptidase for degradation. In multiple crystal structures, some ClpX subunits adopt nucleotide-loadable conformations, others adopt unloadable conformations, and each conformational class exhibits substantial variability. Using mu...

Genetic Algorithms (GAs), as nondeterministic conformational search techniques, are promising for solving protein structure prediction (PSP) problems. The crossover operator of a GA can underpin the formation of potential conformations by exchanging and sharing potential sub-conformations. However, as the optimum PSP conformation is usually compact, the crossover operation may result in many in...

Proteins fluctuate between alternative conformations, which presents a challenge for ligand discovery because such flexibility is difficult to treat computationally owing to problems with conformational sampling and energy weighting. Here we describe a flexible docking method that samples and weights protein conformations using experimentally derived conformations as a guide. The crystallograph...

RNA exhibits a large diversity of conformations. Three thousand nucleotides of 23S and 5S ribosomal RNA from a structure of the large ribosomal subunit were analyzed in order to classify their conformations. Fourier averaging of the six 3D distributions of torsion angles and analyses of the resulting pseudo electron maps, followed by clustering of the preferred combinations of torsion angles we...

In this issue of Molecular Pharmacology, Mukhopadhyay and Howlett present evidence for ligand-selective conformations of the CB1 cannabinoid receptor with differential coupling to G proteins. Ligand-directed signaling to different cellular effector pathways extends drug selectivity beyond that afforded by differential affinity for different receptor subtypes. The challenge for pharmacologists o...