Phylogenetic analysis of known dockerins in Ruminococcus flavefaciens revealed a novel subtype, type-III, in the scaffoldin proteins, ScaA, ScaB, ScaC and ScaE. In this study, we explored the Ca²⁺-binding properties of the type-III dockerin from the ScaA scaffoldin (ScaADoc) using a battery of structural and biophysical approaches including circular dichroism spectroscopy, isothermal titration calorimetry, differential scanning calorimetry, and nuclear magnetic resonance spectroscopy. Despite the lack of a second canonical Ca²⁺-binding loop, the behaviour of ScaADoc is similar with respect to other dockerin protein modules in terms of its responsiveness to Ca²⁺ and affinity for the cohesin from the ScaB scaffoldin. Our results highlight the robustness of dockerin modules and how their Ca²⁺-binding properties can be exploited in the construction of designer cellulosomes.
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http://dx.doi.org/10.1016/j.febslet.2012.11.012 | DOI Listing |
Int J Biol Macromol
January 2023
CIISA-Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisbon, Portugal; Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 1300-477 Lisbon, Portugal. Electronic address:
The cellulosome is an elaborate multi-enzyme structure secreted by many anaerobic microorganisms for the efficient degradation of lignocellulosic substrates. It is composed of multiple catalytic and non-catalytic components that are assembled through high-affinity protein-protein interactions between the enzyme-borne dockerin (Doc) modules and the repeated cohesin (Coh) modules present in primary scaffoldins. In some cellulosomes, primary scaffoldins can interact with adaptor and cell-anchoring scaffoldins to create structures of increasing complexity.
View Article and Find Full Text PDFBiotechnol Biofuels
September 2017
Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel.
Background: is an anaerobic, mesophilic, cellulolytic, cellulosome-producing clostridial bacterium capable of utilizing cellulose and cellobiose as carbon sources. Recently, we sequenced the genome, and subsequent comprehensive bioinformatic analysis, herein reported, revealed an unprecedented number of cellulosome-related components, including 78 cohesin modules scattered among 31 scaffoldins and more than 200 dockerin-bearing ORFs. In terms of numbers, the cellulosome system represents the most intricate, compositionally diverse cellulosome system yet known in nature.
View Article and Find Full Text PDFFEBS Lett
June 2015
Department of Molecular Microbiology and Biotechnology, Tel Aviv University, 69978, Israel; The Daniella Rich Institute for Structural Biology, Tel Aviv University, 69978, Israel.
The cellulolytic bacterium Ruminococcus flavefaciens of the herbivore rumen produces an elaborate cellulosome system, anchored to the bacterial cell wall via the covalently bound scaffoldin ScaE. Dockerin-bearing scaffoldins also bind to an autonomous cohesin of unknown function, called cohesin G (CohG). Here, we demonstrate that CohG binds to the scaffoldin-borne dockerin in opposite orientation on a distinct site, relative to that of ScaE.
View Article and Find Full Text PDFJ Mol Recognit
March 2015
Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel.
Cellulosomes are large multicomponent cellulose-degrading assemblies found on the surfaces of cellulolytic microorganisms. Often containing hundreds of components, the self-assembly of cellulosomes is mediated by the ultra-high-affinity cohesin-dockerin interaction, which allows them to adopt the complex architectures necessary for degrading recalcitrant cellulose. Better understanding of how the cellulosome assembles and functions and what kinds of structures it adopts will further effort to develop industrial applications of cellulosome components, including their use in bioenergy production.
View Article and Find Full Text PDFActa Crystallogr F Struct Biol Commun
April 2014
Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel.
Ruminococcus flavefaciens is a cellulolytic bacterium found in the rumen of herbivores and produces one of the most elaborate and variable cellulosome systems. The structure of an R. flavefaciens protein (RfCohG, ZP_06142108), representing a freestanding (non-cellulosomal) type III cohesin module, has been determined.
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