Cell surface enzyme attachment is mediated by family 37 carbohydrate-binding modules, unique to Ruminococcus albus

The rumen bacterium Ruminococcus albus binds to and degrades crystalline cellulosic substrates via a unique cellulose degradation system. A unique family of carbohydrate-binding modules (CBM37), located at the C terminus of different glycoside hydrolases, appears to be responsible both for anchoring these enzymes to the bacterial cell surface and for substrate binding

Cellulosomics, a gene-centric approach to investigating the intraspecific diversity and adaptation of Ruminococcus flavefaciens within the rumen

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Complexity of the Ruminococcus flavefaciens FD-1 cellulosome reflects an expansion of family-related protein-protein interactions

This work was supported in part by the European Union, Area NMP.2013.1.1–2: Self-assembly of naturally occurring nanosystems: CellulosomePlus Project number: 604530, and by the EU Seventh Framework Programme (FP7 2007–2013) under the WallTraC project (Grant Agreement no 263916), and BioStruct-X (grant agreement no 283570). This paper reflects the author’s views only. The European Community is not liable for any use that may be made of the information contained herein. CMGAF is also supported by Fundação para a Ciência e a Tecnologia (Lisbon, Portugal) through grants PTDC/BIA-PRO/103980/2008 and EXPL/BIA-MIC/1176/2012. EAB is also funded by a grant (No. 1349/13) from the Israel Science Foundation (ISF), Jerusalem, Israel and by a grant (No. 2013284) from the U.S.-Israel Binational Science Foundation (BSF). E.A.B. is the incumbent of The Maynard I. and Elaine Wishner Chair of Bio-organic Chemistry.Peer reviewedPublisher PD

Abundance and Diversity of Dockerin-Containing Proteins in the Fiber-Degrading Rumen Bacterium, Ruminococcus flavefaciens FD-1

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Diversity and Strain Specificity of Plant Cell Wall Degrading Enzymes Revealed by the Draft Genome of Ruminococcus flavefaciens FD-1

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α-Galactosidase Aga27A, an Enzymatic Component of the Clostridium josui Cellulosome

The Clostridium josui aga27A gene encodes the cellulosomal α-galactosidase Aga27A, which comprises a catalytic domain of family 27 of glycoside hydrolases and a dockerin domain responsible for cellulosome assembly. The catalytic domain is highly homologous to those of various α-galactosidases of family 27 of glycoside hydrolases from eukaryotic organisms, especially plants. The recombinant Aga27A α-galactosidase devoid of the dockerin domain preferred highly polymeric galactomannan as a substrate to small saccharides such as melibiose and raffinose

Engineered Platform for Bioethylene Production by a Cyanobacterium Expressing a Chimeric Complex of Plant Enzymes

Ethylene is an industrially important compound, but more sustainable production methods are desirable. Since cellulosomes increase the ability of cellulolytic enzymes by physically linking the relevant enzymes via dockerin–cohesin interactions, in this study, we genetically engineered a chimeric cellulosome-like complex of two ethylene-generating enzymes from tomato using cohesin–dockerins from the bacteria <i>Clostridium thermocellum</i> and <i>Acetivibrio cellulolyticus</i>. This complex was transformed into <i>Escherichia coli</i> to analyze kinetic parameters and enzyme complex formation and into the cyanobacterium <i>Synechococcus elongatus</i> PCC 7942, which was then grown with and without 0.1 mM isopropyl β-d-1-thiogalactopyranoside (IPTG) induction. Only at minimal protein expression levels (without IPTG), the chimeric complex produced 3.7 times more ethylene <i>in vivo</i> than did uncomplexed enzymes. Thus, cyanobacteria can be used to sustainably generate ethylene, and the synthetic enzyme complex greatly enhanced production efficiency. Artificial synthetic enzyme complexes hold great promise for improving the production efficiency of other industrial compounds