The conserved GTPase LepA contributes mainly to translation initiation in Escherichia coli.
Nucleic Acids Res
; 42(21): 13370-83, 2014 Dec 01.
Article
en En
| MEDLINE
| ID: mdl-25378333
LepA is a paralog of EF-G found in all bacteria. Deletion of lepA confers no obvious growth defect in Escherichia coli, and the physiological role of LepA remains unknown. Here, we identify nine strains (ΔdksA, ΔmolR1, ΔrsgA, ΔtatB, ΔtonB, ΔtolR, ΔubiF, ΔubiG or ΔubiH) in which ΔlepA confers a synthetic growth phenotype. These strains are compromised for gene regulation, ribosome assembly, transport and/or respiration, indicating that LepA contributes to these functions in some way. We also use ribosome profiling to deduce the effects of LepA on translation. We find that loss of LepA alters the average ribosome density (ARD) for hundreds of mRNA coding regions in the cell, substantially reducing ARD in many cases. By contrast, only subtle and codon-specific changes in ribosome distribution along mRNA are seen. These data suggest that LepA contributes mainly to the initiation phase of translation. Consistent with this interpretation, the effect of LepA on ARD is related to the sequence of the Shine-Dalgarno region. Global perturbation of gene expression in the ΔlepA mutant likely explains most of its phenotypes.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Iniciación de la Cadena Peptídica Traduccional
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Factores de Iniciación de Péptidos
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Proteínas de Escherichia coli
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Factores Procarióticos de Iniciación
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Escherichia coli
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Nucleic Acids Res
Año:
2014
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Reino Unido