鼠李半乳糖醛酸聚糖裂解酶揭示了多糖裂解酶家族4独特的三结构域模块化结构。

Rhamnogalacturonan lyase reveals a unique three-domain modular structure for polysaccharide lyase family 4.

作者信息

McDonough Michael A, Kadirvelraj Renuka, Harris Pernille, Poulsen Jens-Christian N, Larsen Sine

机构信息

Centre for Crystallographic Studies, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, DK, Denmark.

出版信息

FEBS Lett. 2004 May 7;565(1-3):188-94. doi: 10.1016/j.febslet.2004.03.094.

DOI:10.1016/j.febslet.2004.03.094

PMID:15135077

Abstract

Rhamnogalacturonan lyase (RG-lyase) specifically recognizes and cleaves alpha-1,4 glycosidic bonds between L-rhamnose and D-galacturonic acids in the backbone of rhamnogalacturonan-I, a major component of the plant cell wall polysaccharide, pectin. The three-dimensional structure of RG-lyase from Aspergillus aculeatus has been determined to 1.5 A resolution representing the first known structure from polysaccharide lyase family 4 and of an enzyme with this catalytic specificity. The 508-amino acid polypeptide displays a unique arrangement of three distinct modular domains. Each domain shows structural homology to non-catalytic domains from other carbohydrate active enzymes.

摘要

鼠李半乳糖醛酸裂解酶（RG-裂解酶）能特异性识别并切割鼠李半乳糖醛酸聚糖-I主链中L-鼠李糖和D-半乳糖醛酸之间的α-1,4糖苷键，鼠李半乳糖醛酸聚糖-I是植物细胞壁多糖果胶的主要成分。来自棘孢曲霉的RG-裂解酶的三维结构已确定至1.5埃分辨率，这是多糖裂解酶家族4中首个已知结构，也是具有这种催化特异性的酶的首个已知结构。这个由508个氨基酸组成的多肽呈现出三个不同模块结构域的独特排列。每个结构域都与其他碳水化合物活性酶的非催化结构域具有结构同源性。