Dihydroneopterin aldolase

Goyer, A. et al.. Folate biosynthesis in higher plants. cDNA cloning heterologous expression and characterization of dihydroneopterin aldolases, Plant. Physiol, 135, 103, 2004. 

Dihydroneopterin aldolase (Table 1, entry 8) Inhibitors (such as 33) of dihydro-neopterin aldolase were identified using high throughput X-ray-based fragment screening of a 10,000 member random library [43]. Structure-guided optimisation gave potent leads such as 35. 

Figure 10.1 shows a two-dimensional [15N, H]-TROSY correlation spectrum of the 15N,2H- labeled 110 kDa homo-octameric protein 7,8-dihydroneopterin aldolase from Staphylococcus aureus (DHNA) measured with the pulse sequence of Fig. 10.4 [13]. The gain in spectral resolution and sensitivity is readily apparent from comparison with the corresponding conventional experiment. The optimal sensitivity is achieved by adjusting the polarization transfer r in Fig. 10.4 (3 ms <2r<5.4 ms [3]). For an optimal suppression of the non-TROSY components, the so-called Clean TROSY might be used [19]. Similar signal and spectral resolution enhancements are achieved for 15N,2H-labeled or 13C,15N,2H-...

Folate biosynthesis has also been studied in plants and the dihydroneopterin aldolase from Arabidopsis thaliana has been crystallized and its structure determined the construction of the active site has similarities with those of other... 

The stereochemical course of the reaction catalyzed by dihydroneopterin aldolase has been established <2002JBC28841>. By carrying out the reaction in deuterium oxide and using multinuclear NMR spectroscopy of folate derived from the reaction product, 6-hydroxymethylpterin, it was shown that the late-stage enol intermediate undergoes protonation to form 6-hydroxymethylpterin with deuterium predominantly in the A-configuration. 

The structure of dihydroneopterin aldolase has been analyzed further with respect to the functional roles of conserved active site glutamate and lysine residues <2006B15232>. NMR studies have also suggested that the isomerization of dihydroneopterin to dihydromonapterin catalyzed by the same enzyme involves the action of the same functional groups <2007MI2240>. 

Severin, J. M., Walter, K., Magdalinos, P., Jakob, C. G., Wagner, R., and Beutel, B. A. (2004). Discovery of potent inhibitors of dihydroneopterin aldolase using CrystaLEAD high-throughput X-ray crystallographic screening and structure-directed lead optimization. Journal of Medicinal Chemistry 47, 1709-1718. 

Scherperel, G., Yan, H.G., Wang, Y. and Reid, G.E. (2006) Top-down characterization of site-directed mutagenesis products of Staphylococcus aureus dihydroneopterin aldolase by multistage tandem mass spectrometry in a linear quadrupole ion trap. Analyst, 131, 291-302. 

Figure 2 Biosynthesis of foiates. a, GTP cyclohydrolase I b, dihydroneopterin epimerase c, nudix hydrolase d, phosphatase e, dihydroneopterin aldolase f, hydroxymethyidihydropterin pyrophosphokinase g, dihydropteroate synthase h, dihydrofolate synthetase I, dihydrofolate reductase j, folylpolyglutamate synthetase k, aminodeoxychorismate synthase I, aminodeoxychorismate lyase. 7, 7,8-dihydro-D-neopterin 3 -triphosphate 8, 7,8-dihydro-L-monapterin 3 -triphosphate 9, 7,8-dihydro-D-neopterin 3 -monophosphate 10, 7,8-dihydro-D-neopterin 11, glycolaldehyde ...

As shown in Scheme 12.119, the 7,8-dihydroneopterin undergoes a retroaldol with the liberation of a-hydroxyacetaldehyde to 6-hydroxymethyl-7,8-dihydropterin (dihydroneopterin aldolase, EC 4.1.2.25), which is, in turn, phosphorylated, with ATP being convertedtoAMP(2-amino-4-hydroxy-6-hydroxymethyldihydropteridine diphosphokinase, EC 2.1.63) to yield 6-hydroxymethyl-7,8-dihydropterin diphosphate. 

Garcon, A. et al. (2006) Crystal structure of the bifunctional dihydroneopterin aldolase/6-hydrox5Tnethyl-7,8-dihydropterin pyrophos-phokinase from Streptococcus pneumoniae. J. Mol. Biol. 360, 644-653... 

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