RibB (3,4-dihydroxy-2-butanone 4-phosphate synthase) is a magnesium-dependent enzyme that excises the C4 of d-ribulose-5-phosphate (d-Ru5P) as formate. RibB generates the four-carbon substrate for lumazine synthase that is incorporated into the xylene moiety of lumazine and ultimately the riboflavin isoalloxazine. The reaction was first identified by Bacher and co-workers in the 1990s, and their chemical mechanism hypothesis became canonical despite minimal direct evidence.
View Article and Find Full Text PDFModulating disease-relevant protein-protein interactions (PPIs) using pharmacological tools is a critical step toward the design of novel therapeutic strategies. Over the years, however, targeting PPIs has proven a very challenging task owing to the large interfacial areas. Our recent efforts identified possible novel routes for the design of potent and selective inhibitors of PPIs using a structure-based design of covalent inhibitors targeting Lys residues.
View Article and Find Full Text PDFRAD52 is a structurally and functionally conserved component of the DNA double-strand break (DSB) repair apparatus from budding yeast to humans. We recently showed that expressing the human gene, in mutant budding yeast cells can suppress both their ionizing radiation (IR) sensitivity and homologous recombination repair (HRR) defects. Intriguingly, we observed that supports DSB repair by a mechanism of HRR that conserves genome structure and is independent of the canonical HR machinery.
View Article and Find Full Text PDFMetabolite damage control is a critical but poorly defined aspect of cellular biochemistry, which likely involves many of the so far functionally uncharacterized protein domain (domains of unknown function; DUFs). We have determined the crystal structure of the human DUF89 protein product of the C6ORF211 gene to 1.85 Å.
View Article and Find Full Text PDFThe hydroxyornithine transformylase from Pseudomonas aeruginosa is known by the gene name pvdF, and has been hypothesized to use N-formyltetrahydrofolate (N-fTHF) as a co-substrate formyl donor to convert N-hydroxyornithine (OHOrn) to N-formyl- N-hydroxyornithine (fOHOrn). PvdF is in the biosynthetic pathway for pyoverdin biosynthesis, a siderophore generated under iron-limiting conditions that has been linked to virulence, quorum sensing and biofilm formation. The structure of PvdF was determined by X-ray crystallography to 2.
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