title: Predicting Homogeneous Pilus Structure from Monomeric Data and Sparse Constraints.
abstract: Type IV pili (T4P) and T2SS (Type II Secretion System) pseudopili are filaments extending beyond microbial surfaces, comprising homologous subunits called "pilins." In this paper, we presented a new approach to predict pseudo atomic models of pili combining ambiguous symmetric constraints with sparse distance information obtained from experiments and based neither on electronic microscope (EM) maps nor on accurate a priori symmetric details. The approach was validated by the reconstruction of the gonococcal (GC) pilus from Neisseria gonorrhoeae, the type IVb toxin-coregulated pilus (TCP) from Vibrio cholerae, and pseudopilus of the pullulanase T2SS (the PulG pilus) from Klebsiella oxytoca. In addition, analyses of computational errors showed that subunits should be treated cautiously, as they are slightly flexible and not strictly rigid bodies. A global sampling in a wider range was also implemented and implied that a pilus might have more than one but fewer than many possible intact conformations.
authors.affiliation: State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Xiao
authors.affiliation: State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China.
authors.forename: Chuanjun
authors.initials: C
authors.lastname: Shu
authors.affiliation: State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Yan
authors.affiliation: State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Sun
mesh_terms: D036781:Fimbriae Proteins / Q000737:chemistry / Q000648:ultrastructure*; D010861:Fimbriae, Bacterial / Q000737:chemistry / Q000648:ultrastructure*; D006026:Glycoside Hydrolases / Q000737:chemistry; D041121:Klebsiella oxytoca / Q000737:chemistry / Q000648:ultrastructure; D008958:Models, Molecular; D009344:Neisseria gonorrhoeae / Q000737:chemistry / Q000648:ultrastructure; D000069178:Type II Secretion Systems / Q000648:ultrastructure*; D014734:Vibrio cholerae / Q000737:chemistry / Q000648:ultrastructure
chemical_list: D000069178:Type II Secretion Systems; D036781:Fimbriae Proteins; D006026:Glycoside Hydrolases; C100181:pullulanase