English   español  
Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/51875
Título

Molecular Architecture and Structural Transitions of a Clostridium thermocellum Mini-Cellulosome

AutorGarcía-Alvarez, Begoña; Melero, Roberto ; Dias, Fernando M.V.; Prates, José A.M.; Fontes, Carlos M.G.A.; Smith, Steven P.; Romão, Maria João; Carvalho, Ana Luisa; Llorca, Óscar
Palabras clavecellulosome
CipA
cohesin
dockerin
cryo-EM
Fecha de publicación8-abr-2011
EditorElsevier
CitaciónJournal of Molecular Biology 407(4):571-580(2011)
ResumenThe cellulosome is a highly elaborate cell-bound multienzyme complex that efficiently orchestrates the deconstruction of cellulose and hemicellulose, two of the nature's most abundant polymers. Understanding the intricacy of these nanomachines evolved by anaerobic microbes could sustain the development of an effective process for the conversion of lignocellulosic biomass to bio-ethanol. In Clostridium thermocellum, cellulosome assembly is mediated by high-affinity protein:protein interactions (> 109 M− 1) between dockerin modules found in the catalytic subunits and cohesin modules located in a non-catalytic protein scaffold termed CipA. Whereas the atomic structures of several cellulosomal components have been elucidated, the structural organization of the complete cellulosome remains elusive. Here, we reveal that a large fragment of the cellulosome presents a mostly compact conformation in solution, by solving the three-dimensional structure of a C. thermocellum mini-cellulosome comprising three consecutive cohesin modules, each bound to one Cel8A cellulase, at 35 Å resolution by cryo-electron microscopy. Interestingly, the three cellulosomal catalytic domains are found alternately projected outward from the CipA scaffold in opposite directions, in an arrangement that could expand the area of the substrate accessible to the catalytic domains. In addition, the cellulosome can transit from this compact conformation to a multitude of diverse and flexible structures, where the linkers between cohesin modules are extended and flexible. Thus, structural transitions controlled by changes in the degree of flexibility of linkers connecting consecutive cohesin modules could regulate the efficiency of substrate recognition and hydrolysis
Descripción10 páginas, 4 figuras, 3 suplementos figuras -- PAGS nros. 571-580
Versión del editorhttp://dx.doi.org/10.1016/j.jmb.2011.01.060
URIhttp://hdl.handle.net/10261/51875
DOI10.1016/j.jmb.2011.01.060
ISSN0022-2836
E-ISSN1089-8638
Aparece en las colecciones: (CIB) Artículos
Ficheros en este ítem:
No hay ficheros asociados a este ítem.
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.