HMM Summary Page: TIGR02068

Functioncyanophycin synthetase
Gene SymbolcphA
Trusted Cutoff730.70
Domain Trusted Cutoff730.70
Noise Cutoff319.25
Domain Noise Cutoff319.25
Isology Typeequivalog
EC Number6.3.2.29
HMM Length864
Mainrole CategoryCellular processes
Subrole CategoryBiosynthesis of natural products
Gene Ontology TermGO:0016874: ligase activity molecular_function
GO:0051235: maintenance of location biological_process
AuthorHaft DH
Entry DateDec 2 2003 1:03PM
Last ModifiedDec 19 2011 1:06PM
CommentCyanophycin is an insoluble storage polymer for carbon, nitrogen, and energy, found in most Cyanobacteria. The polymer has a backbone of L-aspartic acid, with most Asp side chain carboxyl groups attached to L-arginine. The polymer is made by this enzyme, cyanophycin synthetase, and degraded by cyanophycinase. Heterologously expressed cyanophycin synthetase in E. coli produces a closely related, water-soluble polymer with some Arg replaced by Lys. It is unclear whether enzymes that produce soluble cyanophycin-like polymers in vivo in non-Cyanobacterial species should be designated as cyanophycin synthetase itself or as a related enzyme. This model makes the designation as cyanophycin synthetase. Cyanophycin synthesis is analogous to polyhydroxyalkanoic acid (PHA) biosynthesis, except that PHA polymers lack nitrogen and may be made under nitrogen-limiting conditions.
ReferencesRM 11976746 RT Evaluation of non-cyanobacterial genome sequences for occurrence of genes encoding proteins homologous to cyanophycin synthetase and cloning of an active cyanophycin synthetase from Acinetobacter sp. strain DSM 587. RA Krehenbrink M, Oppermann-Sanio FB, Steinbuchel A. RL Arch Microbiol. 2002 May;177(5):371-80. Epub 2002 Feb 14.
Genome PropertyGenProp0156: cyanophycin-like storage polymers (HMM)