INVESTIGADORES
SALERNO Graciela Lidia
artículos
Título:
Sucrose-phosphate phosphatase from Anabaena sp. strain PCC 7120: Isolation of the protein and gene revealed significant structural differences from the higher-plant enzyme
Autor/es:
A.C. CUMINO; C. EKEROTH; G.L. SALERNO
Revista:
PLANTA
Editorial:
Springer-Verlag
Referencias:
Lugar: Heidelberg; Año: 2001 vol. 214 p. 250 - 256
ISSN:
0032-0935
Resumen:
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.