The plant VTC2 gene encodes GDP-L-galactose phosphorylase, a rate-limiting enzyme in plant vitamin C biosynthesis. Genes encoding apparent orthologs of VTC2 exist in both mammals, which produce vitamin C by a distinct metabolic pathway, and in the nematode worm Caenorhabditis elegans where vitamin C biosynthesis has not been demonstrated. We have now expressed cDNAs of the human and worm VTC2 h...

Polypeptide chain initiation in mammalian systems is regulated at the level of the guanine nucleotide exchange factor (GEF). This multisubunit protein catalyzes the exchange of GDP bound to eukaryotic initiation factor 2 (eIF-2) for GTP. Although various models have been proposed for its mode of action, the exact sequence of events involved in nucleotide exchange is still uncertain. We have stu...

Glycosylation is an important posttranslational protein modification in all eukaryotes. Besides glycosylphosphatidylinositol (GPI) anchors and N-glycosylation, O-fucosylation has been recently reported in key sporozoite proteins of the malaria parasite. Previous analyses showed the presence of GDP-fucose (GDP-Fuc), the precursor for all fucosylation reactions, in the blood stages of Plasmodium ...

The aim of this study is to the long run relationship among Foreign Direct Investment, Trade (Imports & Exports) and Economic growth for Pakistan. The co-integrating VAR framework is used to find the relationship over the period of 1965 to 2005. The results show that there are two long run relationships exist between GDP, Imports and Exports and FDI. First long run relationship shows that both ...

This study complements existing literature by examining the nexus between energy consumption (EC), CO2 emissions (CE) and economic growth (GDP) in 24 African countries using a panel ARDL approach. The following findings are established. First, there is a long run relationship between EC, CE and GDP. Second, a long term effect from CE to GDP and EC is apparent, with reciprocal paths. Third, the ...

L-colitose and d-perosamine are unusual sugars found in the O-antigens of some Gram-negative bacteria such as Escherichia coli, Vibrio cholerae, and Salmonella enterica, among others. The biosynthetic pathways for these two sugars begin with the formation of GDP-mannose from d-mannose 1-phosphate and GTP followed by the subsequent dehydration and oxidation of GDP-mannose to yield GDP-4-keto-6-d...