KRAS mutations are major drivers of various cancers. Recently, allele-specific inhibitors of the KRAS G12C mutant were developed that covalently modify the thiol of Cys12, thereby trapping KRAS in an inactive GDP-bound state. To study the mechanism of action of the covalent inhibitors in both in vitro and intracellular environments, we used real-time NMR to simultaneously observe GTP hydrolysis and inhibitor binding.
View Article and Find Full Text PDFThe movements of cytoplasmic dynein on microtubule (MT) tracks is achieved by two-way communication between the microtubule-binding domain (MTBD) and the ATPase domain via a coiled-coil stalk, but the structural basis of this communication remains elusive. Here, we regulate MTBD either in high-affinity or low-affinity states by introducing a disulfide bond to the stalk and analyze the resulting structures by NMR and cryo-EM. In the MT-unbound state, the affinity changes of MTBD are achieved by sliding of the stalk α-helix by a half-turn, which suggests that structural changes propagate from the ATPase-domain to MTBD.
View Article and Find Full Text PDFThe deletion of , the gene encoding methyl-CpG-binding protein 2, causes severe breathing defects and developmental anomalies in mammals. In -null mice, impaired GABAergic neurotransmission is demonstrated at the early stage of life. GABAergic dysfunction in neurons in the rostral ventrolateral medulla (RVLM) is considered as a primary cause of breathing abnormality in -null mice, but its molecular mechanism is unclear.
View Article and Find Full Text PDFThe crystal structures of a subunit of the formylglycinamide ribonucleotide amidotransferase, PurS, from Thermus thermophilus, Sulfolobus tokodaii and Methanocaldococcus jannaschii were determined and their structural characteristics were analyzed. For PurS from T. thermophilus, two structures were determined using two crystals that were grown in different conditions.
View Article and Find Full Text PDFObjective: This study evaluated the effects of anacetrapib (ANA) on lipids and safety when administered as monotherapy or in combination with atorvastatin (ATV) in Japanese patients with dyslipidemia.
Methods: Patients (n = 407) were randomized equally to 1 of 10 groups: placebo, ATV 10 mg, ANA 10, 40, 100, or 300 mg once daily, and the same ANA doses in combination with ATV 10 mg. Patients were treated with study medication for 8 weeks and followed for an additional 8 weeks, during which ANA was switched to placebo.
Polyglutamine (polyQ) diseases are inherited neurodegenerative diseases characterized by the aggregation of proteins containing expanded polyQ tract. It has been shown that expanded polyQ tract-containing proteins impair the functions of other cellular proteins. However, quantitative changes of cellular proteins in cells expressing expanded polyQ tract-containing proteins have not been performed.
View Article and Find Full Text PDFActa Crystallogr Sect F Struct Biol Cryst Commun
January 2012
The crystal structure of PurL from Thermus thermophilus HB8 (TtPurL; TTHA1519) was determined in complex with an adenine nucleotide, PO(4)(3-) and Mg(2+) at 2.35 Å resolution. TtPurL consists of 29 α-helices and 28 β-strands, and one loop is disordered.
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