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Título del libro: Stress And Environmental Control Of Gene Expression In Bacteria
Título del capítulo: Genes involved in the formation of desiccationresistant cysts in Azotobacter vinelandii

Autores UNAM:
ELDA GUADALUPE ESPIN OCAMPO;
Autores externos:

Idioma:
Inglés
Año de publicación:
2016
Palabras clave:

Alginate; AlgU; Alkylresorcinols; Gac-Rsm system; Gene expression; Hsp20; RpoS


Resumen:

Azotobacter vinelandii is a soil bacterium able to form desiccation resistant cysts. A cyst consists of a cell named the central body, which is covered by a two-layer capsule: the intine and the exine. The cyst membranes are composed by alkylresorcinols and alkylpirones, which are phenolic lipids. These lipids are also found in the exine layer. Mutants unable to produce alginate are unable to form cysts, while mutations that impair alkylresorcinols lead to the production of cysts with a defective exine that are resistant to desiccation. Upon encystment induction, several regulatory systems activate the expression of genes implicated in the synthesis of the cyst components, of the hsp20 gene encoding a small heat shock protein essential for cyst resistance to desiccation, and of genes involved in other processes related to the formation of cysts. These regulators include the alternative sigma factors AlgU and RpoS, and the global Gac-Rsm system. © 2016 John Wiley & Sons, Inc. All rights reserved.


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