Class of enzymes
Biological assembly of cyanophycinase determined from the organism Synechocystis sp. PCC6803
The catalytic triad of Cyanophycinase is Ser 132, His 174, and Glu 201. Other conserved residues which form a pocket around the serine include: Gln101, Asp172, Gln173, Arg178, Arg180 and Arg183
Cyanophycinase (EC 3.4.15.6 , cyanophycin degrading enzyme , beta-Asp-Arg hydrolysing enzyme , CGPase , CphB , CphE , cyanophycin granule polypeptidase , extracellular CGPase ) is an enzyme .[ 1] [ 2] [ 3] It catalyses the following chemical reaction
[L-Asp(4-L-Arg)]n + H2 O
⇌
{\displaystyle \rightleftharpoons }
[L-Asp(4-L-Arg)]n-1 + L-Asp(4-L-Arg)
The enzyme is highly specific for the branched polypeptide cyanophycin . It is similar to Dipeptidase E , another S51 family serine protease .
^ Obst M, Krug A, Luftmann H, Steinbüchel A (July 2005). "Degradation of cyanophycin by Sedimentibacter hongkongensis strain KI and Citrobacter amalonaticus strain G Isolated from an anaerobic bacterial consortium" . Applied and Environmental Microbiology . 71 (7): 3642–52. Bibcode :2005ApEnM..71.3642O . doi :10.1128/aem.71.7.3642-3652.2005 . PMC 1169039 . PMID 16000772 .
^ Obst M, Oppermann-Sanio FB, Luftmann H, Steinbüchel A (July 2002). "Isolation of cyanophycin-degrading bacteria, cloning and characterization of an extracellular cyanophycinase gene (cphE) from Pseudomonas anguilliseptica strain BI. The cphE gene from P. anguilliseptica BI encodes a cyanophycinhydrolyzing enzyme" . The Journal of Biological Chemistry . 277 (28): 25096–105. doi :10.1074/jbc.m112267200 . PMID 11986309 .
^ Richter R, Hejazi M, Kraft R, Ziegler K, Lockau W (July 1999). "Cyanophycinase, a peptidase degrading the cyanobacterial reserve material multi-L-arginyl-poly-L-aspartic acid (cyanophycin): molecular cloning of the gene of Synechocystis sp. PCC 6803, expression in Escherichia coli, and biochemical characterization of the purified enzyme" . European Journal of Biochemistry . 263 (1): 163–9. doi :10.1046/j.1432-1327.1999.00479.x . PMID 10429200 .