Genome-wide analysis of Acetivibrio cellulolyticus provides a blueprint of an elaborate cellulosome system

BMC Genomics

Research Article

Bernard Henrissat¹  Pedro Coutinho¹  Bareket Dassa²  Edward A Bayer²  Christopher L Hemme³  Yue Huang³  Jizhong Zhou³  Ilya Borovok⁴  Raphael Lamed⁴ 

[1] Architecture et Fonction des Macromolecules Biologiques, CNRS and Universite Aix- Marseilles I & II, Marseilles, France;Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel;Department of Botany and Microbiology, and Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA;Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel;

关键词: Cellulosomics;    Clostridium thermocellum;    Scaffoldin;    Cohesin;    Dockerin;   

DOI  :  10.1186/1471-2164-13-210

 received in 2012-02-21, accepted in 2012-05-30,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundMicrobial degradation of plant cell walls and its conversion to sugars and other byproducts is a key step in the carbon cycle on Earth. In order to process heterogeneous plant-derived biomass, specialized anaerobic bacteria use an elaborate multi-enzyme cellulosome complex to synergistically deconstruct cellulosic substrates. The cellulosome was first discovered in the cellulolytic thermophile, Clostridium thermocellum, and much of our knowledge of this intriguing type of protein composite is based on the cellulosome of this environmentally and biotechnologically important bacterium. The recently sequenced genome of the cellulolytic mesophile, Acetivibrio cellulolyticus, allows detailed comparison of the cellulosomes of these two select cellulosome-producing bacteria.ResultsComprehensive analysis of the A. cellulolyticus draft genome sequence revealed a very sophisticated cellulosome system. Compared to C. thermocellum, the cellulosomal architecture of A. cellulolyticus is much more extensive, whereby the genome encodes for twice the number of cohesin- and dockerin-containing proteins. The A. cellulolyticus genome has thus evolved an inflated number of 143 dockerin-containing genes, coding for multimodular proteins with distinctive catalytic and carbohydrate-binding modules that play critical roles in biomass degradation. Additionally, 41 putative cohesin modules distributed in 16 different scaffoldin proteins were identified in the genome, representing a broader diversity and modularity than those of Clostridium thermocellum. Although many of the A. cellulolyticus scaffoldins appear in unconventional modular combinations, elements of the basic structural scaffoldins are maintained in both species. In addition, both species exhibit similarly elaborate cell-anchoring and cellulosome-related gene- regulatory elements.ConclusionsThis work portrays a particularly intricate, cell-surface cellulosome system in A. cellulolyticus and provides a blueprint for examining the specific roles of the various cellulosomal components in the degradation of complex carbohydrate substrates of the plant cell wall by the bacterium.

【 授权许可】

Unknown   
© Dassa et al.; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.