English   español  
Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/163335
Título

Mechanism of antiactivation at the pseudomonas sp. strain ADP σN-dependent PatzT promoter

AutorPlatero, Ana Isabel ; López-Sánchez, Aroa ; Tomás-Gallardo, Laura ; Santero, Eduardo ; Govantes, Fernando
Fecha de publicación2016
EditorAmerican Society for Microbiology
CitaciónApplied and Environmental Microbiology 82(14): 4350-4362 (2016)
ResumenPatzT is an internal promoter of the atzRSTUVW operon that directs the synthesis of AtzT, AtzU, AtzV, and AtzW, components of an ABC-type cyanuric acid transport system. PatzT is σ dependent, activated by the general nitrogen control regulator NtrC with the assistance of protein integration host factor (IHF), and repressed by the LysR-type transcriptional regulator (LTTR) AtzR. We have used a variety of in vivo and in vitro gene expression and protein-DNA interaction assays to assess the mechanisms underlying AtzR-dependent repression of PatzT. Here, we show that repression only occurs when AtzR and NtrC interact simultaneously with the PatzT promoter region, indicating that AtzR acts as an antiactivator to antagonize activation by NtrC. Furthermore, repression requires precise rotational orientation of the AtzR and NtrC binding sites, strongly suggesting proteinprotein interaction between the two proteins on the promoter region. Further exploration of the antiactivation mechanism showed that although AtzR-dependent repression occurs prior to open complex formation, AtzR does not alter the oligomerization state of NtrC or inhibit NtrC ATPase activity when bound to the PatzT promoter region. Taken together, these results strongly suggest that PatzT-bound AtzR interacts with NtrC to prevent the coupling of NtrC-mediated ATP hydrolysis with the remodeling of the interactions between E-σ and PatzT that lead to open complex formation.
URIhttp://hdl.handle.net/10261/163335
Identificadoresdoi: 10.1128/AEM.00906-16
e-issn: 1098-5336
issn: 0099-2240
Aparece en las colecciones: (CABD) Artículos
Ficheros en este ítem:
Fichero Descripción Tamaño Formato  
accesoRestringido.pdf15,38 kBAdobe PDFVista previa
Visualizar/Abrir
Mostrar el registro completo
 

Artículos relacionados:


NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.