Plant and Cell Physiology Advance Access originally published online on October 20, 2006
Plant and Cell Physiology 2006 47(11):1541-1554; doi:10.1093/pcp/pcl020
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
A Rice Family 9 Glycoside Hydrolase Isozyme with Broad Substrate Specificity for Hemicelluloses in Type II Cell Walls
1Hydraulic and Bio Engineering Research Section, Civil Engineering Research Institute, Technology Center, Taisei Corporation, Nase-cho, Totsuka-ku, Yokohama, 245-0051 Japan
2Wheat and Barley Quality Lab, Department of Wheat and Barley Research, National Institute of Crop Science, 2-1-18 Kannondai, Tsukuba, Ibaraki, 305-8518 Japan
* Corresponding author: E-mail, kouki.yoshida{at}sakura.taisei.co.jp; Fax, +81-45-814-7257.
 |
Abstract |
|---|
An auxin analog, 2,4-D, stimulates the activity of endo-1,4-ß-glucanase (EGase) in rice (Oryza sativa L.). The auxin-induced activity from three protein fractions was purified to homogeneity from primary root tissues (based on SDS–PAGE and isoelectric focusing after Coomassie brilliant blue staining). Amino acid sequencing indicated that the 20 N-terminal amino acid sequence of the three proteins was identical, suggesting that these proteins may be cognates of one EGase gene. An internal amino acid sequence of the the rice EGase (LVGGYYDAGDNVK) revealed that this enzyme belongs to glycosyl hydrolase family 9 (GHF9). The major isoform of this rice GHF9 [molecular weight based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS): 51,216, isoelectric point (pI): 5.5] specifically hydrolyzed 1,4-ß-glycosyl linkages of carboxymethyl (CM)-cellulose, phosphoric acid-swollen cellulose, 1,3-1,4-ß-glucan, arabinoxylan, xylan, glucomannan, cellooligosaccharides [with a degree of polymerization (DP) >3] and 1,4-ß-xylohexaose, indicating a broader substrate range compared with those of other characterized GHF9 enzymes or EGases from higher plants. Hydrolytic products of two major hemicellulosic polysaccharides in type II cell walls treated with the purified enzyme were profiled using high-performance anion exchange chromatography (HPAEC). The results suggested that endolytic attack by rice EGase is not restricted to either the cellulose-like domain of 1,3-1,4-ß-glucan or the unsubstituted 1,4-ß-xylosyl backbone of arabinoxylan, but results in the release of smaller oligosaccharides (DP <6) from graminaceous hemicelluloses. The comparatively broader substrate range of this EGase with respect to ß-1,4-glycan backbones (glucose and xylose) may partly reflect different roles of gramineous and non-gramineous GHF9 enzymes.
Keywords: Auxin - Cell wall - Glycoside hydrolase family 9 - Hemicellulose - Oryza sativa - Rice
Abbreviations: p-ABSF, 4-(2-aminoethyl)benzenesulfonyl fluoride hydrochloride; ADA, N-(2-acetamide)-iminodiacetic acid; CM, carboxymethyl; DC, degree of carboxymethylation; DP, degree of polymerization; DTT, dithiothreitol; EGase, endo-1,4-ß-glucanase; GAX, glucuronoarabinoxylan; GHF, glycosyl hydrolase family; HIC, hydrophobic interaction chromatography; HPAEC, high-performance anion exchange chromatography; IEF, isoelectric focusing; LEP, endoproteinase Lys-C; MALDI-TOF MS, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.
(Received July 17, 2006; Accepted October 6, 2006)
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  T. Kimpara, T. Aohara, K. Soga, K. Wakabayashi, T. Hoson, Y. Tsumuraya, and T. Kotake {beta}-1,3 : 1,4-Glucan Synthase Activity in Rice Seedlings under Water Ann. Bot., August 1, 2008; 102(2): 221 - 226. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. R. Urbanowicz, A. B. Bennett, E. del Campillo, C. Catala, T. Hayashi, B. Henrissat, H. Hofte, S. J. McQueen-Mason, S. E. Patterson, O. Shoseyov, et al. Structural Organization and a Standardized Nomenclature for Plant Endo-1,4-beta-Glucanases (Cellulases) of Glycosyl Hydrolase Family 9 Plant Physiology, August 1, 2007; 144(4): 1693 - 1696. [Full Text] [PDF]
|
|
|
|
 |
|
 K. Yoshida, N. Imaizumi, S. Kaneko, Y. Kawagoe, A. Tagiri, H. Tanaka, K. Nishitani, and K. Komae Carbohydrate-Binding Module of a Rice Endo-{beta}-1,4-glycanase, OsCel9A, Expressed in Auxin-Induced Lateral Root Primordia, is Post-Translationally Truncated Plant Cell Physiol., November 1, 2006; 47(11): 1555 - 1571. [Abstract] [Full Text] [PDF]
|
|