Disease relevance of ECs3936

• Collectively, the results demonstrate that MTb GS is a substrate for E. coli ATase, but only low adenylylation states are accessible [1].
• Thus, the use of agents which deplete ATase such as O6-benzylguanine (O6-beG), as a tumour sensitisation strategy is likely further to potentiate collateral toxicity in bone marrow [2].
• The cDNA of human amidophosphoribosyltransferase (EC 2.4.2.14, ATase), which is the supposed regulatory allosteric enzyme of de novo purine nucleotide biosynthesis, has been cloned from human hepatoma (HepG2) cDNA library [3].

High impact information on ECs3936

• We demonstrate that ATase has two active sites; AT-N carries a deadenylylation activity and AT-C carries an adenylylation activity [4].
• The site of adenylylation of MTb GS by the E. coli ATase is Tyr-406, as indicated by the lack of adenylylation of the Y406F mutant, and, as expected, is based on amino acid sequence alignments [1].
• The cDNA of rat amidophosphoribosyltransferase (EC 2.4.2.14, ATase), which is the supposed regulatory allosteric enzyme of de novo purine nucleotide biosynthesis, has been cloned by polymerase chain reaction [5].
• Southern blot analysis suggested that the ATase gene exists as a single copy in the rat genome [5].
• One mutant form of GlnK, containing the alteration R47W, was observed to lack specifically the ability to activate the NRII phosphatase in vitro; it was able to be uridylylated by the UTase/UR and to activate the adenylylation activity of ATase [6].

Chemical compound and disease context of ECs3936

• Our results show that the spin-labeled ATP (Tempo-ATP) serves as a substrate in the glutamine synthesis reaction and in the adenylation of E. coli glutamine synthetase catalyzed by ATP: glutamine adenylyl transferase (ATase) with essentially the same effectiveness as normal ATP [7].

Biological context of ECs3936

• Here we show that a G140H mutation in ATase, introducing the typical His of the conserved sequence region I of the alpha-amylase family, changed ATase into an enzyme with 4-alpha-glucanotransferase activity (3.4 micromol min(-1) mg(-1)) [8].
• Substrate-specificity studies suggested that the lactococcal AspC has ATase activity only with aspartic acid (Asp) [9].
• The predicted open reading frame encodes a protein of 517 amino acids with a deduced molecular weight (Mr) of 57,398, which is consistent with the molecular mass of 56 kDa on SDS-polyacrylamide gel electrophoresis (SDS-PAGE) of the ATase subunit purified from human placenta [3].

Anatomical context of ECs3936

• The data suggest that transfer and expression of O6-beG resistant ATase in normal progenitor cells, should be a useful therapeutic strategy to protect the cells from the cytotoxic effects of the O6-alkylating agents even when used in combination with tumour sensitising agents such as O6-beG [2].

Associations of ECs3936 with chemical compounds

• The wild-types, rad1-1 and rad6-1 yeast expressing the bacterial ATase showed increased resistance to the toxic and mutagenic effects of N-methyl-N'-nitro-N- nitrosoguanidine (MNNG) [10].
• A model for the regulation of ATase by glutamine, PII, and PII-UMP consistent with all data is presented [11].
• Acarviosyl transferase (ATase) from Actinoplanes sp. SE50/110 is a bacterial enzyme that transfers the acarviosyl moiety of the diabetic drug acarbose to sugar acceptors [8].
• A cDNA encoding the human O6-alkylguanine-DNA alkyltransferase (ATase; EC 2.1.1.63; methylated-DNA: protein-cysteine methyltransferase) has been manipulated to generate a C-terminally deleted protein which retains full methyl-transfer activity [12].
• These results suggest that only one lactococcal ATase is involved in the conversion of oxaloacetate to Asp, and Asp biosynthesis is required for the growth of L. lactis LM0230 in milk [9].

Other interactions of ECs3936

• Glutamine acted as an allosteric regulator of both ATase and UTase/UR [13].
• The glutamine synthetase adenylyltransferase (EC 2.7.7.42), WHIch catalyzes the adenylylation and deadenylylation of glutamine synthetase in E. coli, has been stabilized and purified 2200-fold to apparent homogeneity [14].

Analytical, diagnostic and therapeutic context of ECs3936

• Northern blot analysis revealed that ATase is expressed at a high level in brain, heart, liver, and stomach [5].
• Here, we demonstrate via electrospray ionization mass spectrometry that GS from pathogenic M. tuberculosis is adenylylated by the Escherichia coli ATase [1].

References