A core of three amino acids at the carboxyl-terminal region of glutamine synthetase defines its regulation in cyanobacteria

© 2015 John Wiley & Sons Ltd. 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 f...

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Detalles Bibliográficos
Autores: Saelices, Lorena, Robles-Rengel, Rocío, Florencio, Francisco J., Muro-Pastor, M. Isabel
Tipo de recurso: artículo
Fecha de publicación:2015
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/115414
Acceso en línea:http://hdl.handle.net/10261/115414
Access Level:acceso abierto
Palabra clave:Synechocystis 6803
Posttranscriptional Regulation
Inactivating Factors
Glutamine Synthetase
Protein-Protein Interaction
Descripción
Sumario:© 2015 John Wiley & Sons Ltd. 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.