人甘露糖结合蛋白碳水化合物识别结构域通过三股α-螺旋卷曲螺旋形成三聚体。

Human mannose-binding protein carbohydrate recognition domain trimerizes through a triple alpha-helical coiled-coil.

作者信息

Sheriff S, Chang C Y, Ezekowitz R A

机构信息

Bristol-Myers Squibb Pharmaceutical Research Institute, Princeton, NJ 08543-4000, USA.

出版信息

Nat Struct Biol. 1994 Nov;1(11):789-94. doi: 10.1038/nsb1194-789.

DOI:10.1038/nsb1194-789

PMID:7634089

Abstract

Human mannose-binding protein is a hexamer of trimers with each subunit consisting of an amino-terminal region rich in cysteine, 19 collagen repeats, a 'neck', and a carbohydrate recognition domain that requires calcium to bind ligand. A 148-residue peptide, consisting of the 'neck' and carbohydrate recognition domains forms trimers in solution and in crystals. The structure of this trimeric peptide has been determined in two different crystal forms. The 'neck' forms a triple alpha-helical coiled-coil. Each alpha-helix interacts with a neighbouring carbohydrate recognition domain. The spatial arrangement of the carbohydrate recognition domains suggest how MBP trimers form the basic recognition unit for branched oligosaccharides on microorganisms.

摘要

人甘露糖结合蛋白是一种三聚体的六聚体，每个亚基由富含半胱氨酸的氨基末端区域、19个胶原蛋白重复序列、一个“颈部”和一个需要钙来结合配体的碳水化合物识别结构域组成。一个由“颈部”和碳水化合物识别结构域组成的148个残基的肽在溶液和晶体中形成三聚体。这种三聚体肽的结构已通过两种不同的晶体形式确定。“颈部”形成一个三重α-螺旋卷曲螺旋。每个α-螺旋与相邻的碳水化合物识别结构域相互作用。碳水化合物识别结构域的空间排列表明了甘露糖结合蛋白三聚体如何形成对微生物上分支寡糖的基本识别单元。