Asparagine synthase (glutamine-hydrolysing)

Asparagine synthase (glutamine-hydrolysing) (EC 6.3.5.4, asparagine synthetase (glutamine-hydrolysing), glutamine-dependent asparagine synthetase, asparagine synthetase B, AS, AS-B) is an enzyme with systematic name L-aspartate:L-glutamine amido-ligase (AMP-forming). This enzyme catalyses the following chemical reaction

ATP + L-aspartate + L-glutamine + H₂O

\rightleftharpoons

AMP + diphosphate + L-asparagine + L-glutamate (overall reaction)

(1a) L-glutamine + H₂O

\rightleftharpoons

L-glutamate + NH₃

(1b) ATP + L-aspartate + NH₃

\rightleftharpoons

AMP + diphosphate + L-asparagine

The enzyme from Escherichia coli has two active sites.

References

Patterson MK, Orr GR (January 1968). "Asparagine biosynthesis by the Novikoff Hepatoma isolation, purification, property, and mechanism studies of the enzyme system". The Journal of Biological Chemistry. 243 (2): 376–80. PMID 4295091.
Boehlein SK, Richards NG, Schuster SM (March 1994). "Glutamine-dependent nitrogen transfer in Escherichia coli asparagine synthetase B. Searching for the catalytic triad". The Journal of Biological Chemistry. 269 (10): 7450–7. PMID 7907328.
Richards NG, Schuster SM (1998). "Mechanistic issues in asparagine synthetase catalysis". Advances in Enzymology and Related Areas of Molecular Biology. 72: 145–98. PMID 9559053.
Larsen TM, Boehlein SK, Schuster SM, Richards NG, Thoden JB, Holden HM, Rayment I (December 1999). "Three-dimensional structure of Escherichia coli asparagine synthetase B: a short journey from substrate to product". Biochemistry. 38 (49): 16146–57. CiteSeerX 10.1.1.453.5998. doi:10.1021/bi9915768. PMID 10587437.
Huang X, Holden HM, Raushel FM (2001). "Channeling of substrates and intermediates in enzyme-catalyzed reactions". Annual Review of Biochemistry. 70: 149–80. doi:10.1146/annurev.biochem.70.1.149. PMID 11395405.
^ Tesson AR, Soper TS, Ciustea M, Richards NG (May 2003). "Revisiting the steady state kinetic mechanism of glutamine-dependent asparagine synthetase from Escherichia coli". Archives of Biochemistry and Biophysics. 413 (1): 23–31. doi:10.1016/s0003-9861(03)00118-8. PMID 12706338.

External links

Asparagine+synthase+(glutamine-hydrolysing) at the U.S. National Library of Medicine Medical Subject Headings (MeSH)

v t e Enzymes: CO CS and CN ligases (EC 6.1-6.3)
6.1: Carbon-Oxygen	Aminoacyl tRNA synthetase Alanine Arginine Asparagine Aspartate Cysteine D-alanine—poly(phosphoribitol) ligase Glutamate Glutamine Glycine Histidine Isoleucine Leucine Lysine Methionine Phenylalanine Proline Serine Threonine Tryptophan Tyrosine Valine
6.2: Carbon-Sulfur	Succinyl coenzyme A synthetase Acetyl—CoA synthetase Long-chain-fatty-acid—CoA ligase
6.3: Carbon-Nitrogen	Glutamine synthetase Ubiquitin ligase Cullin Von Hippel–Lindau tumor suppressor UBE3A Mdm2 Anaphase-promoting complex UBR1 Glutathione synthetase CTP synthetase Adenylosuccinate synthase Argininosuccinate synthase Holocarboxylase synthetase GMP synthase Asparagine synthetase Carbamoyl phosphate synthetase I II Glutamate–cysteine ligase

v t e Enzymes
Activity	Active site Binding site Catalytic triad Oxyanion hole Enzyme promiscuity Diffusion-limited enzyme Cofactor Enzyme catalysis
Regulation	Allosteric regulation Cooperativity Enzyme inhibitor Enzyme activator
Classification	EC number Enzyme superfamily Enzyme family List of enzymes
Kinetics	Enzyme kinetics Eadie–Hofstee diagram Hanes–Woolf plot Lineweaver–Burk plot Michaelis–Menten kinetics
Types	EC1 Oxidoreductases (list) EC2 Transferases (list) EC3 Hydrolases (list) EC4 Lyases (list) EC5 Isomerases (list) EC6 Ligases (list) EC7 Translocases (list)

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