Evolution of a New Function by Fusion between Phage DNA and a Bacterial Gene.
Mol Biol Evol
; 37(5): 1329-1341, 2020 05 01.
Article
en En
| MEDLINE
| ID: mdl-31977019
ABSTRACT
Mobile genetic elements, such as plasmids, phages, and transposons, are important sources for evolution of novel functions. In this study, we performed a large-scale screening of metagenomic phage libraries for their ability to suppress temperature-sensitivity in Salmonella enterica serovar Typhimurium strain LT2 mutants to examine how phage DNA could confer evolutionary novelty to bacteria. We identified an insert encoding 23 amino acids from a phage that when fused with a bacterial DNA-binding repressor protein (LacI) resulted in the formation of a chimeric protein that localized to the outer membrane. This relocalization of the chimeric protein resulted in increased membrane vesicle formation and an associated suppression of the temperature sensitivity of the bacterium. Both the host LacI protein and the extracellular 23-amino acid stretch are necessary for the generation of the novel phenotype. Furthermore, mutational analysis of the chimeric protein showed that although the native repressor function of the LacI protein is maintained in this chimeric structure, it is not necessary for the new function. Thus, our study demonstrates how a gene fusion between foreign DNA and bacterial DNA can generate novelty without compromising the native function of a given gene.
Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Salmonella typhimurium
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ADN Viral
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Fusión Génica
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Represoras Lac
Idioma:
En
Revista:
Mol Biol Evol
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2020
Tipo del documento:
Article
País de afiliación:
Suecia