Abstract
Arabinogalactan-proteins (AGPs) are a family of complex proteoglycans found in higher plants. AGPs consist of large amounts of carbohydrate components (>90%) having β-3,6-galactan as the backbone frame, whose fine structures and molecular functions are remained to be determined.
We have cloned an endo-β-1,6-galactanase (Tv6GAL) from Trichoderma viride and an α-L-arabinofuranosidase (RsAraf) from radish as useful tools for the structural and functional analyses of AGPs. RsAraf releases L-arabinofuranose residues from native AGPs purified from radish [1]. Tv6GAL hydrolyzes β-1,6-galactosyl side chains of α-L-arabinofuranosidase-treated AGPs. Tv6GAL appeared to be a novel member of family 5 glycosyl hydrolase based on its amino acid sequence [2]. We are constructing transgenic Arabidopsis by introducing RsAraf and/or Tv6GAL to analyze the molecular functions of the carbohydrate moieties of AGPs.
[1] Hata K. et al. (1992) Plant Physiol. 100: 388-396
[2] Kotake et al. (2004) Biochem. J. (in press)
