Formylation of the initiator tRNA is essential for normal growth of Escherichia coli. The initiator tRNA containing the U35A36 mutation (CUA anticodon) initiates from UAG codon. However, an additional mutation at position 72 (72A --> G) renders the tRNA (G72/U35A36) inactive in initiation because it is defective in formylation. In this study, we isolated U1G72/U35A36 tRNA containing a wobble ba...

The mitochondrion of Trypanosoma brucei lacks tRNA genes. Its translation system therefore depends on the import of cytosolic, nucleus-encoded tRNAs. Thus, most trypanosomal tRNAs function in both the cytosol and the mitochondrion, and all are of the eukaryotic type. This is also the case for the elongator tRNA(Met), whereas the only other trypanosomal tRNA(Met), the eukaryotic initiator, is fo...

We show that the two most important properties needed for a tRNA to function in initiation in Escherichia coli are its ability to be formylated and its ability to bind to the ribosomal P site. This conclusion is based on conversion of two different elongator tRNAs to ones that can act as initiators in E. coli. We transplanted the features unique to E. coli and eubacterial initiator tRNAs to E. ...

The N-formyltransferases, also known as transformylases, play key roles in de novo purine biosynthesis where they catalyze the transfer of formyl groups to primary amine acceptors. These enzymes require N10-formyltetrahydrofolate for activity. Due to their biological importance they have been extensively investigated for many years, and they are still serving as targets for antifolate drug desi...

Oral administration of folate analogues to rats is followed by a rise in plasma folate detectable only by micro-biological assay with Lactobacillus casei, suggesting methylation of folate during absorption. When using the everted rat gut technique with folate (PteGlu), dihydrofolate (H(2)PteGlu), or tetrahydrofolate (H(4)PteGlu) on the mucosal surface formyl folate (10-CHO-PteGlu, 10-CHO-H(4)Pt...

Trimethoprim is a specific inhibitor of dihydrofolate reductase. When added to amino acid supplemented cultures of Escherichia coli, protein, ribonucleic acid (RNA), and deoxyribonucleic acid synthesis are rapidly inhibited. It is shown that thymidylate and purine synthesis must continuously occur if the inhibition is to be maintained. These results are interpreted as demonstrating that in vivo...

Synthesizing azoles from ortho-substituted anilines, CO2 and H2 has proved difficult due to the low nucleophilicity of which hinders their N-formylation, i.e., first step reaction. Herein, we demonstrate that R3SnX Lewis acids (LA), N-methylmorpholine (NMM) or DBU polyethyleneimine (PEI) N-formylmorpholine efficiently catalyse synthesis benzimidazole other by reductive coupling nucleophilic ami...