TY - JOUR
T1 - A core of three amino acids at the carboxyl-terminal region of glutamine synthetase defines its regulation in cyanobacteria
AU - Saelices, Lorena
AU - Robles-Rengel, Rocío
AU - Florencio, Francisco J.
AU - Muro-Pastor, M. Isabel
N1 - Publisher Copyright:
© 2015 John Wiley & Sons Ltd.
PY - 2015/5/1
Y1 - 2015/5/1
N2 - Glutamine synthetase (GS) type I is a key enzyme in nitrogen metabolism, and its activity is finely controlled by cellular carbon/nitrogen balance. In cyanobacteria, a reversible process that involves protein-protein interaction with two proteins, the inactivating factors IF7 and IF17, regulates GS. Previously, we showed that three arginine residues of IFs are critical for binding and inhibition of GS. In this work, taking advantage of the specificity of GS/IFs interaction in the model cyanobacteria Synechocystis sp. PCC 6803 and Anabaena sp. PCC 7120, we have constructed a different chimeric GSs from these two cyanobacteria. Analysis of these proteins, together with a site-directed mutagenesis approach, indicates that a core of three residues (E419, N456 and R459) is essential for the inactivation process. The three residues belong to the last 56 amino acids of the C-terminus of SynechocystisGS. A protein-protein docking modeling of SynechocystisGS in complex with IF7 supports the role of the identified core for GS/IF interaction.
AB - Glutamine synthetase (GS) type I is a key enzyme in nitrogen metabolism, and its activity is finely controlled by cellular carbon/nitrogen balance. In cyanobacteria, a reversible process that involves protein-protein interaction with two proteins, the inactivating factors IF7 and IF17, regulates GS. Previously, we showed that three arginine residues of IFs are critical for binding and inhibition of GS. In this work, taking advantage of the specificity of GS/IFs interaction in the model cyanobacteria Synechocystis sp. PCC 6803 and Anabaena sp. PCC 7120, we have constructed a different chimeric GSs from these two cyanobacteria. Analysis of these proteins, together with a site-directed mutagenesis approach, indicates that a core of three residues (E419, N456 and R459) is essential for the inactivation process. The three residues belong to the last 56 amino acids of the C-terminus of SynechocystisGS. A protein-protein docking modeling of SynechocystisGS in complex with IF7 supports the role of the identified core for GS/IF interaction.
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U2 - 10.1111/mmi.12950
DO - 10.1111/mmi.12950
M3 - Article
C2 - 25626767
AN - SCOPUS:84928435591
SN - 0950-382X
VL - 96
SP - 483
EP - 496
JO - Molecular Microbiology
JF - Molecular Microbiology
IS - 3
ER -