title: 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.
abstract: The branched polypeptide multi-L-arginyl-poly-L-aspartic acid, also called cyanophycin, is a water-insoluble reserve material of cyanobacteria. The polymer is degraded by a specific hydrolytic enzyme called cyanophycinase. By heterologous expression in Escherichia coli, a gene encoding cyanophycinase has been identified in the sequenced genome of Synechocystis sp. PCC 6803. The gene, designated cphB, codes for a protein of 29.4 kDa. The high level of expression of active cyanophycinase in E. coli from the Synechocystis gene allowed for its purification to electrophoretic homogeneity. The enzyme, which appears to be specific for cyanophycin, hydrolysed the polymer to a dipeptide consisting of aspartic acid and arginine. Based on inhibitor sensitivity and primary sequence, cyanophycinase appears to be a serine-type exopeptidase related to dipeptidase E [Conlin, C.A., Haakensson, K., Liljas, A. & Miller, C.G. (1994) J. Bacteriol. 176, 166-172].
authors.affiliation: Biochemie der Pflanzen, Humboldt-Universität, Berlin, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Richter
authors.forename: M
authors.initials: M
authors.lastname: Hejazi
authors.forename: R
authors.initials: R
authors.lastname: Kraft
authors.forename: K
authors.initials: K
authors.lastname: Ziegler
authors.forename: W
authors.initials: W
authors.lastname: Lockau
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D001483:Base Sequence; D003001:Cloning, Molecular; D000458:Cyanobacteria / Q000201:enzymology* / Q000235:genetics*; D017931:DNA Primers / Q000235:genetics; D004150:Dipeptidases / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D005798:Genes, Bacterial; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D010447:Peptide Hydrolases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism*; D011480:Protease Inhibitors / Q000494:pharmacology; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012486:Salmonella typhimurium / Q000201:enzymology / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D017931:DNA Primers; D010940:Plant Proteins; D011480:Protease Inhibitors; D011994:Recombinant Proteins; C024250:cyanophycin; D010447:Peptide Hydrolases; C120585:cyanophycinase; D004150:Dipeptidases; C042430:aspartyl peptidase E