Heterotrimeric guanine-nucleotide-binding proteins (G proteins) serve as molecular switches in signalling pathways, by coupling the activation of cell surface receptors to intracellular responses. Mutations in the G protein α-subunit (Gα) that accelerate guanosine diphosphate (GDP) dissociation cause hyperactivation of the downstream effector proteins, leading to oncogenesis. However, the struc...

The phosphorylation of eukaryotic initiation factor (eIF) 2a that occurs when rabbit reticulocyte lysate is incubated in the absence of hemin or with poly(1 .C) causes inhibition of polypeptide chain initiation by preventing a separate factor (termed RF) from promoting the exchange of GTP for GDP on eIF-2. When lysate was incubated in the presence of h min and [‘“C] eIF-2 or [CI-~~PIGTP, we obs...

Strain GS, a gram-negative motile bacterium isolated from soil, synthesizes two polysaccharides. The synthesis of a uranic acid-containing polysaccharide is derepressed by high concentrations of Na2SOd, while the synthesis of the polysaccharide containing equal quantities of n-rhamnose and n-talomethylose is repressed by NazS01 (1, 2). L-F’ucose and L-rhamnose are the methylpentoses commonly fo...

GDP-L-fucose is the activated nucleotide sugar form of L-fucose, which is a constituent of many structural polysaccharides and glycoproteins in various organisms. The de novo synthesis of GDP-L-fucose from GDP-D-mannose encompasses three catalytic steps, a 4,6-dehydration, a 3,5-epimerization, and a 4-reduction. The mur1 mutant of Arabidopsis is deficient in L-fucose in the shoot and is rescued...

INTRODUCTION Nucleoside diphosphate kinase (NDK), conserved across bacteria to humans, synthesises NTP from NDP and ATP. The eukaryotic homologue, the NDPK, uses ATP to phosphorylate the tubulin-bound GDP to GTP for tubulin polymerisation. The bacterial cytokinetic protein FtsZ, which is the tubulin homologue, also uses GTP for polymerisation. Therefore, we examined whether NDK can interact wit...

The 4-amino-6-deoxy-monosaccharide D-perosamine is an important element in the glycosylation of interesting cell products, such as antibiotics and lipopolysaccharides (LPS) of Gram-positive and Gram-negative bacteria. The biosynthetic pathway of the precursor molecule, GDP-D-perosamine, in Vibrio cholerae O1 starts with an isomerisation of fructose-6-phosphate catalyzed by the bifunctional enzy...

Since the 1998 “wind of falsification and embellishment,” Chinese official GDP statistics have repeatedly come under scrutiny. This paper evaluates the quality of China’s GDP statistics in four stages. First, it reviews past and ongoing suspicions of the quality of GDP data and examines the evidence. Second, it documents the institutional framework for data compilation and concludes on the impl...

Muscarinic agonists and adenyl nucleotides are noncompetitive modulators of sites labeled by [35S]GTP gamma S in washed cardiac membranes from Syrian golden hamsters. Specific binding of the radioligand and its inhibition by either GTP gamma S or GDP reveals three states of affinity for guanyl nucleotides. In the absence of adenyl nucleotide, carbachol promotes an apparent interconversion of si...