Asparagine synthase (glutamine-hydrolysing)
{{Infobox enzyme
| Name = Asparagine synthase (glutamine-hydrolysing)
| EC_number = 6.3.5.4
| CAS_number = 37318-72-2
| GO_code =
| image = 1ct9.jpg
| width = 270
| caption = Asparagine synthetase B dimer, E.Coli
}}
Asparagine synthase (glutamine-hydrolysing) ({{EnzExplorer|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).{{cite journal | vauthors = Patterson MK, Orr GR | title = Asparagine biosynthesis by the Novikoff Hepatoma isolation, purification, property, and mechanism studies of the enzyme system | journal = The Journal of Biological Chemistry | volume = 243 | issue = 2 | pages = 376–80 | date = January 1968 | pmid = 4295091 }}{{cite journal | vauthors = Boehlein SK, Richards NG, Schuster SM | title = Glutamine-dependent nitrogen transfer in Escherichia coli asparagine synthetase B. Searching for the catalytic triad | journal = The Journal of Biological Chemistry | volume = 269 | issue = 10 | pages = 7450–7 | date = March 1994 | pmid = 7907328 }}{{cite journal | vauthors = Richards NG, Schuster SM | title = Mechanistic issues in asparagine synthetase catalysis | journal = Advances in Enzymology and Related Areas of Molecular Biology | volume = 72 | pages = 145–98 | year = 1998 | pmid = 9559053 }}{{cite journal | vauthors = Larsen TM, Boehlein SK, Schuster SM, Richards NG, Thoden JB, Holden HM, Rayment I | title = Three-dimensional structure of Escherichia coli asparagine synthetase B: a short journey from substrate to product | journal = Biochemistry | volume = 38 | issue = 49 | pages = 16146–57 | date = December 1999 | pmid = 10587437 | doi = 10.1021/bi9915768 | citeseerx = 10.1.1.453.5998 }}{{cite journal | vauthors = Huang X, Holden HM, Raushel FM | title = Channeling of substrates and intermediates in enzyme-catalyzed reactions | journal = Annual Review of Biochemistry | volume = 70 | pages = 149–80 | year = 2001 | pmid = 11395405 | doi = 10.1146/annurev.biochem.70.1.149 }}{{cite journal | vauthors = Tesson AR, Soper TS, Ciustea M, Richards NG | title = Revisiting the steady state kinetic mechanism of glutamine-dependent asparagine synthetase from Escherichia coli | journal = Archives of Biochemistry and Biophysics | volume = 413 | issue = 1 | pages = 23–31 | date = May 2003 | pmid = 12706338 | doi = 10.1016/s0003-9861(03)00118-8 }} This enzyme catalyses the following chemical reaction
: ATP + L-aspartate + L-glutamine + H2O AMP + diphosphate + L-asparagine + L-glutamate (overall reaction)
: (1a) L-glutamine + H2O L-glutamate + NH3
: (1b) ATP + L-aspartate + NH3 AMP + diphosphate + L-asparagine
The enzyme from Escherichia coli has two active sites.
References
{{reflist}}
External links
- {{MeshName|Asparagine+synthase+(glutamine-hydrolysing)}}
{{Ligases CO CS and CN}}
{{Enzymes}}
{{Portal bar|Biology|border=no}}
{{ligase-stub}}