A complex gene locus enables xyloglucan utilization in the model saprophyte Cellvibrio japonicus. Issue 2 (17th September 2014)

• Record Type: Journal Article
• Authors: Larsbrink, Johan; Thompson, Andrew J.; Lundqvist, Magnus; Gardner, Jeffrey G.; Davies, Gideon J.; Brumer, Harry
• Is Part Of: Molecular microbiology. Volume 94:Issue 2(2014)
• Page Start: 418
• Page End: 433
• Publication Date: 2014-09-17
• Subjects: Molecular microbiology -- Periodicals; 572.829
• DOI: 10.1111/mmi.12776
• Languages: English
• ISSNs: 0950-382X

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>The degradation of plant biomass by saprophytes is an ecologically important part of the global carbon cycle, which has also inspired a vast diversity of industrial enzyme applications. The xyloglucans (XyGs) constitute a family of ubiquitous and abundant plant cell wall polysaccharides, yet the enzymology of XyG saccharification is poorly studied. Here, we present the identification and molecular characterization of a complex genetic locus that is required for xyloglucan utilization by the model saprophyte <italic>C</italic><italic>ellvibrio japonicus</italic>. In harness, transcriptomics, reverse genetics, enzyme kinetics, and structural biology indicate that the encoded cohort of an α‐xylosidase, a β‐galactosidase, and an α‐<sc>l</sc>‐fucosidase is specifically adapted for efficient, concerted saccharification of dicot (fucogalacto)xyloglucan oligosaccharides following import into the periplasm via an associated TonB‐dependent receptor. The data support a biological model of xyloglucan degradation by <italic>C</italic><italic>. japonicus</italic> with striking similarities – and notable differences – to the complex polysaccharide utilization loci of the Bacteroidetes.</p> </abstract>