2uwb
From Proteopedia
CRYSTAL STRUCTURE OF THE NASTURTIUM SEEDLING MUTANT XYLOGLUCANASE ISOFORM NXG1-DELTA-YNIIG
Overview
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-DeltaYNIIG 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.
About this Structure
2UWB is a Single protein structure of sequence from Tropaeolum majus. Full crystallographic information is available from OCA.
Reference
Structural evidence for the evolution of xyloglucanase activity from xyloglucan endo-transglycosylases: biological implications for cell wall metabolism., Baumann MJ, Eklof JM, Michel G, Kallas AM, Teeri TT, Czjzek M, Brumer H 3rd, Plant Cell. 2007 Jun;19(6):1947-63. Epub 2007 Jun 8. PMID:17557806 Page seeded by OCA on Sun May 4 17:39:09 2008
