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Expression of the glutamyl‐tRNA synthetase gene from the cyanobacterium Synechococcus sp. PCC 7942 depends on nitrogen availability and the global regulator NtcA
Author(s) -
Luque Ignacio,
Contreras Asunción,
Zabulon Gérald,
Herrero Antonia,
Houmard Jean
Publication year - 2002
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1046/j.1365-2958.2002.03236.x
Subject(s) - biology , synechococcus , gene , psychological repression , cyanobacteria , regulator , transcriptional regulation , transfer rna , regulation of gene expression , bacteria , genetics , gene expression , biochemistry , rna
Summary We report here transcriptional analyses of a cyanobacterial gene encoding an aminoacyl‐tRNA synthetase (aaRS), the gltX gene from Synechoccocus sp. PCC 7942, coding for the glutamyl‐tRNA synthetase. We show that the transcript levels of gltX in Synechococcus depend on nitrogen availability and do not increase with the growth rate, which is at odds with observations from other bacteria. We also demonstrate the involvement of the cyanobacterial global regulator NtcA in transcriptional control of gltX according to nitrogen status. Our results support a regulatory model in which the gltX transcript level is finely tuned by a dynamic equilibrium between activation and repression relying upon the cellular concentration of NtcA.