Structural modeling of two plant UDP-dependent sugar-sugar glycosyltransferases reveals a conserved glutamic acid residue that is a hallmark for sugar acceptor recognition.

Glycosylation is one of the common modifications of plant metabolites, playing a major role in the chemical/biological diversity of a wide range of compounds. Plant metabolite glycosylation is catalyzed almost exclusively by glycosyltransferases, mainly by Uridine-diphosphate dependent Glycosyltransferases (UGTs). Several X-ray structures have been determined for primary glycosyltransferases, however, little is known regarding structure-function aspects of sugar-sugar/branch-forming O-linked UGTs (SBGTs) that catalyze the transfer of a sugar from the UDP-sugar donor to an acceptor sugar moiety of a previously glycosylated metabolite substrate.

Augmenting Structure-Based Design with Experimental Protein-Ligand Interaction Data: Molecular Recognition, Interactive Visualization, and Rescoring.

The previously introduced ratio of frequencies (R ) framework provides statistically sound information on the relative interaction preferences of atoms in crystal structures. By applying the methodology to protein-ligand complexes, we can investigate the significance of interactions that are employed in structure-based drug design. Here, we revisit three aspects of molecular recognition in the light of the R framework, namely stacking interactions of heteroaromatic rings with protein amide groups, interactions of acidified C-H groups, and interaction differences between syn and anti lone pairs of carboxylate groups.

The α-Terpineol to 1,8-Cineole Cyclization Reaction of Tobacco Terpene Synthases.

Flowers of Nicotiana species emit a characteristic blend including the cineole cassette monoterpenes. This set of terpenes is synthesized by multiproduct enzymes, with either 1,8-cineole or α-terpineol contributing most to the volatile spectrum, thus referring to cineole or terpineol synthase, respectively. To understand the molecular and structural requirements of the enzymes that favor the biochemical formation of α-terpineol and 1,8-cineole, site-directed mutagenesis, in silico modeling, and semiempiric calculations were performed.

Regions outside of conserved PxxPxR motifs drive the high affinity interaction of GRB2 with SH3 domain ligands.

SH3 domains are evolutionarily conserved protein interaction domains that control nearly all cellular processes in eukaryotes. The current model is that most SH3 domains bind discreet PxxPxR motifs with weak affinity and relatively low selectivity. However, the interactions of full-length SH3 domain-containing proteins with ligands are highly specific and have much stronger affinity.

Decreased range of motion is associated with structural hip deformity in asymptomatic adolescent athletes.

Background: Decreased hip range of motion (ROM) is a common finding in patients with femoroacetabular impingement (FAI).

Purpose: To report the prevalence of decreased hip ROM in asymptomatic adolescent athletes and to correlate examination findings to signs of FAI on radiographs and magnetic resonance imaging (MRI).

Study Design: Cross-sectional study (prevalence); Level of evidence, 3.