title: Symmetric key structural residues in symmetric proteins with beta-trefoil fold.
abstract: To understand how symmetric structures of many proteins are formed from asymmetric sequences, the proteins with two repeated beta-trefoil domains in Plant Cytotoxin B-chain family and all presently known beta-trefoil proteins are analyzed by structure-based multi-sequence alignments. The results show that all these proteins have similar key structural residues that are distributed symmetrically in their structures. These symmetric key structural residues are further analyzed in terms of inter-residues interaction numbers and B-factors. It is found that they can be distinguished from other residues and have significant propensities for structural framework. This indicates that these key structural residues may conduct the formation of symmetric structures although the sequences are asymmetric.
authors.affiliation: Biophysics and Molecular Modeling Group, Department of Physics, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Jianhui
authors.initials: J
authors.lastname: Feng
authors.forename: Mingfeng
authors.initials: M
authors.lastname: Li
authors.forename: Yanzhao
authors.initials: Y
authors.lastname: Huang
authors.forename: Yi
authors.initials: Y
authors.lastname: Xiao
mesh_terms: D000465:Algorithms; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001665:Binding Sites / Q000235:genetics; D003603:Cytotoxins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D017510:Protein Folding; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D003603:Cytotoxins; D010940:Plant Proteins