Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1832526 (PCC)
 5,967 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The present study describes the first isolation and characterization of a prokaryotic protein and gene for sucrose-phosphate phosphatase (SPP), the enzyme that catalyzes the terminal step in sucrose synthesis. For gene isolation, a 2,015-bp DNA fragment containing an open reading frame with about 31% amino acid identity to Synechocystis SPS was amplified from Anabaena sp. PCC 7120 DNA. Surprisingly, expression of the putative gene in Escherichia coli demonstrated that it encoded an SPP protein. The expressed protein cross-reacted with antibodies against the native form of Anabaena SPP and its biochemical properties were identical to those of the enzyme purified from the cyanobacterial cells. Comparisons of the Anabaena SPP with the higher-plant enzyme revealed important differences in the C-terminal region, molecular mass, subunit composition and immunoreactivity. Nevertheless, two conserved motifs, including four invariant aspartate residues similar to those found in members of the phosphohydrolase superfamily, were identified in the Anabaena SPP deduced amino acid sequence.
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PMID:Sucrose-phosphate phosphatase from Anabaena sp. strain PCC 7120: isolation of the protein and gene revealed significant structural differences from the higher-plant enzyme. 1180 Mar 89

The role of sucrose in cyanobacteria is still not fully understood. It is generally considered a salt-response molecule, and particularly, in Synechocystis sp. strain PCC 6803, it is referred as a secondary osmolyte. We showed that sucrose accumulates transiently in Synechocystis cells at early stages of a salt shock, which could be ascribed to salt activation of sucrose-phosphate synthase (SPS, UDP-glucose: D-fructose-6-phosphate 2-alpha-D-glucosyltransferase; EC 2.4.1.14), the key enzyme in sucrose synthesis pathway, and to an increase of the expression of the SPS encoding gene. Experiments with a mutant strain impaired in sucrose biosynthesis showed that sucrose is essential in stationary phase cells to overcome a later salt stress. Taken together, these results led us to suggest a more intricate function for sucrose than to be an osmoprotectant compound.
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PMID:Sucrose may play an additional role to that of an osmolyte in Synechocystis sp. PCC 6803 salt-shocked cells. 1582 Jun 60