title: The Structure of Physarum polycephalum hemagglutinin I suggests a minimal carbohydrate recognition domain of legume lectin fold.
abstract: Physarum polycephalum hemagglutinin I (HA1) is a 104-residue protein that is secreted to extracellular space. The crystal structure of HA1 has a β-sandwich fold found among lectin structures, such as legume lectins and galectins. Interestingly, the β-sandwich of HA1 lacks a jelly roll motif and is essentially composed of two simple up-and-down β-sheets. This up-and-down β-sheet motif is well conserved in other legume lectin-like proteins derived from animals, plants, bacteria, and viruses. It is more noteworthy that the up-and-down β-sheet motif includes many residues that make contact with the target carbohydrates. Our NMR data demonstrate that HA1 lacking a jelly roll motif also binds to its target glycopeptide. Taken together, these data show that the up-and-down β-sheet motif provides a fundamental scaffold for the binding of legume lectin-like proteins to the target carbohydrates, and the structure of HA1 suggests a minimal carbohydrate recognition domain.
authors.affiliation: Department of Structural Biology, University of Toyama, Toyama 930-0194, Japan. konox005@umn.edu
authors.forename: Takahide
authors.initials: T
authors.lastname: Kouno
authors.forename: Nobuhisa
authors.initials: N
authors.lastname: Watanabe
authors.forename: Naoki
authors.initials: N
authors.lastname: Sakai
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakamura
authors.forename: Yuko
authors.initials: Y
authors.lastname: Nabeshima
authors.forename: Masashi
authors.initials: M
authors.lastname: Morita
authors.forename: Mineyuki
authors.initials: M
authors.lastname: Mizuguchi
authors.forename: Tomoyasu
authors.initials: T
authors.lastname: Aizawa
authors.forename: Makoto
authors.initials: M
authors.lastname: Demura
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Imanaka
authors.forename: Isao
authors.initials: I
authors.lastname: Tanaka
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kawano
mesh_terms: D002241:Carbohydrates / Q000737:chemistry*; D007887:Fabaceae / Q000737:chemistry*; D006020:Glycopeptides / Q000737:chemistry / Q000378:metabolism; D037102:Lectins / Q000737:chemistry* / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D016839:Physarum polycephalum / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D017510:Protein Folding; D055503:Protein Multimerization
chemical_list: D002241:Carbohydrates; D006020:Glycopeptides; D037102:Lectins; C112408:hemagglutinin I