Preliminary X-ray characterization of a novel type of anchoring cohesin from the cellulosome ofRuminococcus flavefaciens

Abstract

Ruminococcus flavefaciens is an anaerobic bacterium that resides in the gastrointestinal tract of ruminants. It produces a highly organized multi-enzyme cellulosome complex that plays a key role in the degradation of plant cell walls. ScaE is one of the critical structural components of its cellulosome that serves to anchor the complex to the cell wall. The seleno-l-methionine-labelled derivative of the ScaE cohesin module has been cloned, expressed, purified and crystallized. The crystals belong to space group C2, with unit-cell parameters a = 155. 6, b = 69.3, c = 93.0 Å , = 123.4 , and contain four molecules in the asymmetric unit. Diffraction data were phased to 1.95 Å using the anomalous signal from the Se atoms.

Noncellulosomal cohesin- and dockerin-like modules in the three domains of life

“…The discovery of cellulosomes in Ruminococcus flavefaciens has contributed additional diverse types of cohesin modules to the overall repertoire (Ding et al, 2001;Rincon et al, 2003Rincon et al, , 2004Rincon et al, , 2005. However, the nine-stranded b-sandwich and jellyroll topology appears to be a definitive structural characteristic of the cohesin fold (Alber et al, 2008).…”

Atypical Cohesin-Dockerin Complex Responsible for Cell Surface Attachment of Cellulosomal Components

“…To date, only the single type IIIe CohE crystal structure from R. flavefaciens strain 17 has been reported (26,27). A planar region at the 8-3-6-5 face of the molecule bordered by ␤-flap 8 has been proposed to play a role in type IIIe dockerin recognition and specificity.…”

Crystallization and preliminary X-ray characterization of a type III cohesin–dockerin complex from the cellulosome system ofRuminococcus flavefaciens

“…Expression of the native and seleno-l-methionine-labelled CohE module (residues 30-230) from R. flavefaciens ScaE scaffoldin and of the XDoc dyad from CttA scaffoldin (residues 565-803) was conducted according to the method described previously (Van Duyne et al, 1993;Alber et al, 2008). CohE and XDoc were expressed in 1 and 0.75 l cell culture, respectively.…”

“…To date, the structures of several type I and type II Coh-Doc complexes have been solved, thereby providing direct insight into the mode of interaction between the two modular counterparts in Clostridium thermocellum and C. cellulolyticum (Carvalho et al, 2003(Carvalho et al, , 2007Adams et al, 2006Adams et al, , 2010Pinheiro et al, 2008). A single type III cohesin structure from R. flavefaciens strain 17 has been reported to date (Alber et al, 2008(Alber et al, , 2009, but the achievement of a structural description of a type III Coh-Doc complex has remained challenging. Here, we report the cloning, expression, co-purification, crystallization and preliminary X-ray characterization of a type III RfCohE-XDoc complex between CohE and the C-terminal XDoc dyad of CttA from R. flavefaciens strain FD-1.…”