Plant Cell SoftGenetics
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
QUICK SEARCH:   [advanced]


     

Plant Cell Advance Online Publication
Published on June 8, 2007; 10.1105/tpc.107.051391

This Article
Right arrow Full Text - TPC Advance Online Pub. (PDF)
Right arrow Supplemental Data
Right arrow All Versions of this Article:
19/6/1947    most recent
tpc.107.051391v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Baumann, M. J.
Right arrow Articles by Brumer, H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Baumann, M. J.
Right arrow Articles by Brumer, H., III
Agricola
Right arrow Articles by Baumann, M. J.
Right arrow Articles by Brumer, H.

Received March 1, 2007
Returned for revision May 3, 2007
Accepted May 16, 2007

Structural Evidence for the Evolution of Xyloglucanase Activity from Xyloglucan Endo-Transglycosylases: Biological Implications for Cell Wall Metabolism

Martin J. Baumann 1, Jens M. Eklöf 1, Gurvan Michel 2, Åsa M. Kallas 1, Tuula T. Teeri 1, Mirjam Czjzek 2*, and Harry Brumer III 1

1 School of Biotechnology, Royal Institute of Technology, AlbaNova University Center, S-10691 Stockholm, Sweden
2 Equipe Glycobiologie Marine, Unité Mixte de Recherche 7139, Végétaux Marins et Biomolécules, Centre National de la Recherche Scientifique/Université Pierre et Marie Curie-Paris 6, Station Biologique, 29682 Roscoff, Bretagne, France

* To whom correspondence should be addressed. E-mail: czjzek{at}sb-roscoff.fr.

High-resolution, three-dimensional structures of the archetypal glycoside hydrolase family 16 (GH16) endo-xyloglucanases Tm-NXG1 and Tm-NXG2 from nasturtium (Tropaeolum majus) have been solved by x-ray crystallography. Key structural features that modulate the relative rates of substrate hydrolysis to transglycosylation in the GH16 xyloglucan-active enzymes were identified by structure-function studies of the recombinantly expressed enzymes in comparison with data for the strict xyloglucan endo-transglycosylase Ptt-XET16-34 from hybrid aspen (Populus tremula x Populus tremuloides). Production of the loop deletion variant Tm-NXG1-{Delta}YNIIG yielded an enzyme that was structurally similar to Ptt-XET16-34 and had a greatly increased transglycosylation:hydrolysis ratio. Comprehensive bioinformatic analyses of XTH gene products, together with detailed kinetic data, strongly suggest that xyloglucanase activity has evolved as a gain of function in an ancestral GH16 XET to meet specific biological requirements during seed germination, fruit ripening, and rapid wall expansion.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
ASPB Publications THE PLANT CELL PLANT PHYSIOLOGY
Copyright © 2007 by the American Society of Plant Biologists