Literature summary for 2.3.1.4 extracted from

Hurtado-Guerrero, R.; Raimi, O.; Shepherd, S.; van Aalten, D.M.
Glucose-6-phosphate as a probe for the glucosamine-6-phosphate N-acetyltransferase Michaelis complex (2007), FEBS Lett., 581, 5597-5600.

Crystallization (Commentary)

Crystallization (Comment)	Organism
using the pseudo-substrate glucose-6-phosphate as a probe with GNA1 crystals, the first GNAT (pseudo-)Michaelis complex is trapped. The complex shows optimal alignment under the ideal Burgi-Dunitz angle for direct nucleophilic attack of the sugar amine, and suggests protonation of the tetrahedral intermediate may proceed through intramolecular proton transfer facilitated by a favourably positioned backbone carbonyl. The hydrogen bond established between the hydroxyl group of Tyr174 and the thioester sulfur increase the electrophilic character of the carbonyl group, favouring the direct nucleophilic attack by the glucosamine 6-phosphate, explaining the 500fold decrease in the turnover when Tyr174 is mutated to Phe, providing direct evidence for the nucleophilic attack of the substrate amine, and giving insight into the protonation of the thiolate leaving group	Aspergillus fumigatus

Crystallization (Comment)

Organism

using the pseudo-substrate glucose-6-phosphate as a probe with GNA1 crystals, the first GNAT (pseudo-)Michaelis complex is trapped. The complex shows optimal alignment under the ideal Burgi-Dunitz angle for direct nucleophilic attack of the sugar amine, and suggests protonation of the tetrahedral intermediate may proceed through intramolecular proton transfer facilitated by a favourably positioned backbone carbonyl. The hydrogen bond established between the hydroxyl group of Tyr174 and the thioester sulfur increase the electrophilic character of the carbonyl group, favouring the direct nucleophilic attack by the glucosamine 6-phosphate, explaining the 500fold decrease in the turnover when Tyr174 is mutated to Phe, providing direct evidence for the nucleophilic attack of the substrate amine, and giving insight into the protonation of the thiolate leaving group

Aspergillus fumigatus

Protein Variants

Protein Variants	Comment	Organism
Y174F	crystal structure of the mutant Y174F acetyl-CoA/glucose-6-P complex is indistinguishable from the wild-type complex, mutant displays some remaining activity, kcat: 0.076/sec (glucosamine 6-phosphate)	Aspergillus fumigatus

Inhibitors

Inhibitors	Comment	Organism	Structure
glucose-6-phosphate	weak competitive inhibitor	Aspergillus fumigatus

KM Value [mM]

KM Value [mM]	KM Value Maximum [mM]	Substrate	Comment	Organism	Structure
0.071	-	glucosamine 6-phosphate	-	Aspergillus fumigatus

Organism

Organism	UniProt	Comment	Textmining
Aspergillus fumigatus	-	-	-

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
acetyl-CoA + D-glucosamine 6-phosphate	-	Aspergillus fumigatus	CoA + N-acetyl-D-glucosamine 6-phosphate	-	?

Synonyms

Synonyms	Comment	Organism
AfGNA1	-	Aspergillus fumigatus
glucosamine-6-phosphate N-acetyltransferase	-	Aspergillus fumigatus

Temperature Optimum [°C]

Temperature Optimum [°C]	Temperature Optimum Maximum [°C]	Comment	Organism
additional information	-	assay carried out at room temperature	Aspergillus fumigatus

Turnover Number [1/s]

Turnover Number Minimum [1/s]	Turnover Number Maximum [1/s]	Substrate	Comment	Organism	Structure
0.076	-	glucosamine 6-phosphate	mutant Y174F	Aspergillus fumigatus
38	-	glucosamine 6-phosphate	wild-type	Aspergillus fumigatus

pH Optimum

pH Optimum Minimum	pH Optimum Maximum	Comment	Organism
7.5	-	assay at	Aspergillus fumigatus

Ki Value [mM]

Ki Value [mM]	Ki Value maximum [mM]	Inhibitor	Comment	Organism	Structure
2.6	-	glucose-6-phosphate	-	Aspergillus fumigatus