title: Models of the actin-bound forms of the beta-thymosins.
abstract: In recent years two structures have been reported that demonstrate how the two halves of a beta-thymosin repeat bind to actin monomers. Here we assess the validity of these structures and construct minimally biased models of the beta-thymosin:actin complexes. The models reveal that the beta-thymosins interact with actin throughout their length and that all the conserved residues are functional in this interface. These models are judged to be in excellent agreement with published biochemical and functional data. In particular, the models are consistent with the actin monomer sequestering and actin filament binding properties of beta-thymosins. The models also correctly predict competition between thymosin-beta4 with DNase I or profilin in binding actin while allowing ternary complexes at higher concentrations.
authors.affiliation: Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, Singapore 138673. rrobinson@imcb.a-star.edu.sg
authors.forename: Bo
authors.initials: B
authors.lastname: Xue
authors.forename: Adeleke Halilu
authors.initials: AH
authors.lastname: Aguda
authors.forename: Robert Charles
authors.initials: RC
authors.lastname: Robinson
mesh_terms: D000199:Actins / Q000737:chemistry* / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D016384:Consensus Sequence; D008958:Models, Molecular; D011485:Protein Binding; D011487:Protein Conformation; D013947:Thymosin / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000378:metabolism; D000099201:Thymosin beta(4)
chemical_list: D000199:Actins; D013947:Thymosin; D000099201:Thymosin beta(4)