2024-03-29T04:40:42Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1422192017-04-07T07:17:59Zcom_10261_118com_10261_6col_10261_497
The lack of GlnB and YejB compensates the detrimetal effect of spoT deletion in E. coli cells expressing wild type relA
Montero, Manuel
Almagro, Goizeder
Viale, Alejandro M.
Sevilla, Ángel
Cánovas, Manuel
Bernal, Cristina
Lozano, Ana Belén
Muñoz Pérez, Francisco José
Baroja-Fernández, Edurne
Pozueta Romero, Javier
Trabajo presentado en el XXXVII Congreso de la Sociedad Española de Bioquímica y Biología Molecular (SEBBM), celbrado en Granada del 9 al 12 de septiembre de 2014.
In Escherichia coli, intracellular ppGpp content in response to nutritional
deficiency is controlled by the balanced action of RelA (synthetase I) and
the dual-function (synthetase/hydrolase) SpoT. Generally ascribed to the
detrimental effects of high (p)ppGpp levels, the co-existence of
spoT null (DspoT) with relA proficient alleles has been considered synthetically lethal.
However, in a recent work we have reported the construction of DspoT
mutants in a relA+background accumulating nearly wild type (WT) ppGpp levels when cells were cultured on a rich complex medium. Sequencing of the genomes from various selected DspoT clones identified in all of them suppressor mutations located in relA. In two of them, additional inactivating mutations were found in glnB and yejB, two genes that have not been characterized as genetically linked to relA.
To know whether mutations resulting in the total abolishment of the
glnB and yejB genes could compensate the detrimental effects of spoT
deletions in E. coli in this work we obtained multiple independent DspoTDglnB and DspoTDyejB clones. Importantly, these clones expressed WT RelA,
displayed a nearly WT growth phenotype, and accumulated nearly WT ppGpp and glycogen contents when cultured in a rich complex medium.
None of these mutants, however, could grow on glucose minimal medium. The
overall data (a) show that different mutations other than in relA can be selected
in E. coli cells compensating the detrimental effects of spoT deletion, and (b)
point to the occurrence in E. coli of mechanism(s), other than SpoT-mediated
ppGpp hydrolytic breakdown, that prevent ppGpp over-accumulation. To our
knowledge this is the first report describing the production of spoT
null mutants of E. coli expressing WT RelA.
2017-01-05T11:51:07Z
2017-01-05T11:51:07Z
2014-09
2017-01-05T11:51:08Z
póster de congreso
XXXVII Congreso de la Sociedad Española de Bioquímica y Biología Molecular (2014)
http://hdl.handle.net/10261/142219
eng
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