Structure-function analysis of a broad specificity Populus trichocarpa endo-β-glucanase reveals an evolutionary link between bacterial licheninases and plant XTH gene products
2013 (English)In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 288, no 22, 15786-15799 p.Article in journal (Refereed) Published
The large xyloglucan endotransglycosylase/hydrolase (XTH) gene family continues to be the focus of much attention in studies of plant cell wall morphogenesis due to the unique catalytic functions of the enzymes it encodes. The XTH gene products compose a subfamily of glycoside hydrolase family 16 (GH16), which also comprises a broad range of microbial endoglucanases and endogalactanases, as well as yeast cell wall chitin/β-glucan transglycosylases. Previous whole-family phylogenetic analyses have suggested that the closest relatives to the XTH gene products are the bacterial licheninases (EC 220.127.116.11), which specifically hydrolyze linear mixed linkage β(1→3)/β(1→4)-glucans. In addition to their specificity for the highly branched xyloglucan polysaccharide, XTH gene products are distinguished from the licheninases and other GH16 enzyme subfamilies by significant active site loop alterations and a large C-terminal extension. Given these differences, the molecular evolution of the XTH gene products in GH16 has remained enigmatic. Here, we present the biochemical and structural analysis of a unique, mixed function endoglucanase from black cottonwood (Populus trichocarpa), which reveals a small, newly recognized subfamily of GH16 members intermediate between the bacterial licheninases and plant XTH gene products. We postulate that this clade comprises an important link in the evolution of the large plant XTH gene families from a putative microbial ancestor. As such, this analysis provides new insights into the diversification of GH16 and further unites the apparently disparate members of this important family of proteins. © 2013 by The American Society for Biochemistry and Molecular Biology, Inc.
Place, publisher, year, edition, pages
2013. Vol. 288, no 22, 15786-15799 p.
Broad specificities, C-terminal extensions, Catalytic functions, Glycoside hydrolase family 16, Molecular evolution, Phylogenetic analysis, Populus trichocarpa, Structure-function analysis, Catalysis, Enzyme activity, Molecular biology, Plant cell culture, Plants (botany), Polymers, Genes, bacterial enzyme, endo beta glucanase, glucan synthase, licheninase, unclassified drug, article, cladistics, enzyme specificity, enzyme structure, multigene family, nucleotide sequence, plant gene, priority journal, structure activity relation, XTH gene, Carbohydrate Processing, Cellulase, Enzyme Kinetics, Glycoside Hydrolases, Plant Cell Wall, Polysaccharide, Xyloglucan, Xyloglucan Endotransglycosylase/Hydrolase (XTH), Bacterial Proteins, Catalytic Domain, Evolution, Molecular, Glycosyltransferases, Phylogeny, Plant Proteins, Populus, Protein Structure, Secondary
Biochemistry and Molecular Biology
IdentifiersURN: urn:nbn:se:kth:diva-134447DOI: 10.1074/jbc.M113.462887ISI: 000319822300033ScopusID: 2-s2.0-8487838277OAI: oai:DiVA.org:kth-134447DiVA: diva2:676674
FunderSwedish Research CouncilFormas
QC 201312062013-12-062013-11-252013-12-20Bibliographically approved