Peroxiredoxins (Prxs) make up an ancient family of enzymes that are the predominant peroxidases for nearly all organisms and play essential roles in reducing hydrogen peroxide, organic hydroperoxides, and peroxynitrite. Even between distantly related organisms, the core protein fold and key catalytic residues related to its cysteine-based catalytic mechanism have...
Sedoheptulose 7-phosphate cyclases (SH7PCs) encompass three enzymes involved in producing the core cyclitol structures of pseudoglycosides and similar bioactive natural products. One such enzyme is ValA from Streptomyces hygroscopicus subsp. jinggangensis 5008 which makes 2-epi-5-epi-valiolone as part of the biosynthesis of the agricultural antifungal agent validamycin A. We present, as...
The site-specific incorporation of non-canonical amino acids (ncAAs) into proteins is an important tool for understanding biological function. Traditionally, each new ncAA targeted requires a resource-consuming process of generating new ncAA aminoacyl tRNA synthetase/tRNACUA pairs. However, the discovery that some tRNA synthetases are “permissive,” in that they can incorporate multiple...
The Escherichia coli sulfur starvation utilization (ssu) operon includes a two-component monooxygenase system made up of an NADPH-dependent FMN reductase, SsuE, and a monooxygenase, SsuD. SsuE is part of the flavodoxin-like superfamily, and we report here the crystal structures of its apo, FMN-bound and FMNH₂-bound forms at ~2 Å resolution....
Ideal values of bond angles and lengths used as external restraints are crucial for the successful
refinement of protein crystal structures at all but the highest of resolutions. The restraints in
common usage today have been designed based on the assumption that each type of bond or
angle has a...