Distinguishing Vaccinium species by chemical fingerprinting based on NMR spectra, validated with spectra collected in different laboratories.

A method was developed to distinguish Vaccinium species based on leaf extracts using nuclear magnetic resonance spectroscopy. Reference spectra were measured on leaf extracts from several species, including lowbush blueberry (Vaccinium angustifolium), oval leaf huckleberry (Vaccinium ovalifolium), and cranberry (Vaccinium macrocarpon). Using principal component analysis, these leaf extracts were resolved in the scores plot.

The interaction between eukaryotic initiation factor 1A and eIF5 retains eIF1 within scanning preinitiation complexes.

Scanning of the mRNA transcript by the preinitiation complex (PIC) requires a panel of eukaryotic initiation factors, which includes eIF1 and eIF1A, the main transducers of stringent AUG selection. eIF1A plays an important role in start codon recognition; however, its molecular contacts with eIF5 are unknown. Using nuclear magnetic resonance, we unveil eIF1A's binding surface on the carboxyl-terminal domain of eIF5 (eIF5-CTD).

The C-terminal domain of eukaryotic initiation factor 5 promotes start codon recognition by its dynamic interplay with eIF1 and eIF2β.

Recognition of the proper start codon on mRNAs is essential for protein synthesis, which requires scanning and involves eukaryotic initiation factors (eIFs) eIF1, eIF1A, eIF2, and eIF5. The carboxyl terminal domain (CTD) of eIF5 stimulates 43S preinitiation complex (PIC) assembly; however, its precise role in scanning and start codon selection has remained unknown. Using nuclear magnetic resonance (NMR) spectroscopy, we identified the binding sites of eIF1 and eIF2β on eIF5-CTD and found that they partially overlapped.

Mechanistic pathways in CF3COOH-mediated deacetalization reactions.

It has been widely accepted that both the protection of carbonyls and the deprotection of acetals and ketals involve the participation of a water molecule: formation of acetals and ketals is a dehydration process, whereas the deprotection is often referred to as hydrolysis, which, as implied by its name, always requires the presence of water. Herein, we report experimental evidence and mechanistic investigations that provide an alternative view to this process. We have demonstrated that water is not required to convert acetals and ketals to the corresponding carbonyls.

The structure of free L11 and functional dynamics of L11 in free, L11-rRNA(58 nt) binary and L11-rRNA(58 nt)-thiostrepton ternary complexes.

The L11 binding site is one of the most important functional sites in the ribosome. The N-terminal domain of L11 has been implicated as a "reversible switch" in facilitating the coordinated movements associated with EF-G-driven GTP hydrolysis. The reversible switch mechanism has been hypothesized to require conformational flexibility involving re-orientation and re-positioning of the two L11 domains, and warrants a close examination of the structure and dynamics of L11.