cyanophycin synthase (L-aspartate-adding)

{{Short description|Class of enzymes}}

{{Infobox enzyme

| Name = Cyanophycin synthase (L-aspartate-adding)

| EC_number = 6.3.2.29

| CAS_number = 131554-17-1

| GO_code =

| image =

| width =

| caption =

}}

{{Infobox nonhuman protein

|Organism=Synechocystis sp. PCC 6803

|Symbol=cphA

|UniProt=P73833

}}

Cyanophycin synthase (L-aspartate-adding) ({{EnzExplorer|6.3.2.29}}, CphA, CphA1, CphA2, cyanophycin synthetase, multi-L-arginyl-poly-L-aspartate synthase) is an enzyme with systematic name cyanophycin:L-aspartate ligase (ADP-forming).{{cite journal | vauthors = Aboulmagd E, Oppermann-Sanio FB, Steinbüchel A | title = Molecular characterization of the cyanophycin synthetase from Synechocystis sp. strain PCC6308 | journal = Archives of Microbiology | volume = 174 | issue = 5 | pages = 297–306 | date = November 2000 | pmid = 11131019 | doi = 10.1007/s002030000206 }}{{cite journal | vauthors = Aboulmagd E, Oppermann-Sanio FB, Steinbüchel A | title = Purification of Synechocystis sp. strain PCC6308 cyanophycin synthetase and its characterization with respect to substrate and primer specificity | journal = Applied and Environmental Microbiology | volume = 67 | issue = 5 | pages = 2176–82 | date = May 2001 | pmid = 11319097 | pmc = 92852 | doi = 10.1128/AEM.67.5.2176-2182.2001 }}{{cite journal | vauthors = Allen MM, Hutchison F, Weathers PJ | title = Cyanophycin granule polypeptide formation and degradation in the cyanobacterium Aphanocapsa 6308 | journal = Journal of Bacteriology | volume = 141 | issue = 2 | pages = 687–93 | date = February 1980 | pmid = 6767688 | pmc = 293676 }}{{cite journal | vauthors = Berg H, Ziegler K, Piotukh K, Baier K, Lockau W, Volkmer-Engert R | title = Biosynthesis of the cyanobacterial reserve polymer multi-L-arginyl-poly-L-aspartic acid (cyanophycin): mechanism of the cyanophycin synthetase reaction studied with synthetic primers | journal = European Journal of Biochemistry | volume = 267 | issue = 17 | pages = 5561–70 | date = September 2000 | pmid = 10951215 | doi = 10.1046/j.1432-1327.2000.01622.x | doi-access = free }}{{cite journal | vauthors = Ziegler K, Deutzmann R, Lockau W | title = Cyanophycin synthetase-like enzymes of non-cyanobacterial eubacteria: characterization of the polymer produced by a recombinant synthetase of Desulfitobacterium hafniense | journal = Zeitschrift für Naturforschung C | volume = 57 | issue = 5-6 | pages = 522–9 | year = 2002 | pmid = 12132696 | doi = 10.1515/znc-2002-5-621 | doi-access = free }}{{cite journal | vauthors = Ziegler K, Diener A, Herpin C, Richter R, Deutzmann R, Lockau W | title = Molecular characterization of cyanophycin synthetase, the enzyme catalyzing the biosynthesis of the cyanobacterial reserve material multi-L-arginyl-poly-L-aspartate (cyanophycin) | journal = European Journal of Biochemistry | volume = 254 | issue = 1 | pages = 154–9 | date = May 1998 | pmid = 9652408 | doi = 10.1046/j.1432-1327.1998.2540154.x | doi-access = free }} This enzyme catalyses the following chemical reaction

: ATP + [L-Asp(4-L-Arg)]n + L-Asp $\backslash rightleftharpoons$ ADP + phosphate + [L-Asp(4-L-Arg)]n-L-Asp

This enzyme requires Mg²⁺ for activity. All enzymes known to have this activity also catalyze the addition of arginine, i.e. cyanophycin synthase (L-arginine-adding) activity. It is structurally similar to Muramyl ligases.