Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.5.1.3 (dihydrofolate reductase)
 5,819 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The involvement of the nucleoside triphosphates in the initiation of the synthesis of the messenger ribonucleic acid of five T4 specific enzymes has been studied. Only one of these, the messenger RNA for deoxynucleosidemonophosphate kinase, can be initiated in the presence of one nucleoside triphosphate, namely ATP. All of the remaining four require the presence of at least two nucleoside triphosphates during the initiation period. The combination of ATP and UTP was best for the initiation of messenger RNA for dihydrofolate reductase, ATP and CTP for deoxycytidylate hydroxymethyltransferase and beta-glucosyltransferase, and ATP and GTP for alpha-glucosyltransferase. We have concluded that there is a great variation in the nucleotide composition and sequence of the initiation sites in T4 DNA. No correlation in the requirements of nucleoside triphosphates during the initiation period could be observed among the five systems studied according to their classification as one type or another of "early" T4 messenger RNA.
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PMID:Initiation characteristics for the synthesis of five T4 phage-specific messenger RNAs in vitro. 436 Sep 43

In the endoplasmic reticulum (ER), nascent glycoproteins that have not acquired the native conformation are either repaired or sorted for degradation by specific quality-control systems composed by various proteins. Among them, UDP-glucose:glycoprotein glucosyltransferase (UGGT) serves as a folding sensor in the ER. However, the molecular mechanism of its recognition remains obscure. This study used pseudo-misfolded glycoproteins, comprising a modified dihydrofolate reductase with artificial pyrene-cysteine moiety on the protein surface (pDHFR) and Man9 GlcNAc2 -methotrexate (M9-MTX). All five M9-MTX/pDHFR complexes, with a pyrene group at different positions, were found to be good substrates of UGGT, irrespective of the site of pyrene modification. These results suggest UGGT's mode of substrate recognition is fuzzy, thus allowing various glycoproteins to be accommodated in the folding cycle.
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PMID:Hydrophobic Tagged Dihydrofolate Reductase for Creating Misfolded Glycoprotein Mimetics. 2667 Jan 96