Download MendeleySolution Structure of the Cbm10 Cellulose Binding Module from Pseudomonas Xylanase A
Raghothama, S., Simpson, P.J., Szabo, L., Nagy, T., Gilbert, H.J., Williamson, M.P.(2000) Biochemistry 39: 978
- PubMed: 10653641
- DOI: https://doi.org/10.1021/bi992163+
- Primary Citation of Related Structures:
1E8R, 1QLD - PubMed Abstract:
Plant cell wall hydrolases generally have a modular structure consisting of a catalytic domain linked to one or more noncatalytic carbohydrate-binding modules (CBMs), whose common function is to attach the enzyme to the polymeric substrate. Xylanase A from Pseudomonas fluorescens subsp. cellulosa (Pf Xyn10A) consists of a family 10 catalytic domain, an N-terminal family IIa cellulose-binding module, and an internal family 10 cellulose-binding module. The structure of the 45-residue family 10 CBM has been determined in solution using NMR. It consists of two antiparallel beta-sheets, one with two strands and one with three, with a short alpha-helix across one face of the three-stranded sheet. There is a high density of aromatic residues on one side of the protein, including three aromatic residues (Tyr8, Trp22, and Trp24), which are exposed and form a flat surface on one face, in a classical polysaccharide-binding arrangement. The fold is closely similar to that of the oligonucleotide/oligosaccharide-binding (OB) fold, but appears to have arisen by convergent evolution, because there is no sequence similarity, and the presumed binding sites are on different faces.
Organizational Affiliation:
Department of Molecular Biology and Biotechnology, Krebs Institute, University of Sheffield, Sheffield S10 2TN, U.K.
