title: Proposed molten globule intermediates in fd phage penetration and assembly.
abstract: The fd filamentous phage can be contracted to short rods called I-forms and to spheroidal particles called S-forms. The conversions from fd----I-forms----S-forms were previously suggested to mimic steps in fd penetration. The same conversions, in reverse order, were suggested to mimic steps in fd assembly. The I-forms and S-forms bind the hydrophobic probe, 1-anilino-napthalene-8-sulfonate (ANS); under the same conditions, fd binds this probe very poorly. Rigidly packed side chains in fd and nonrigidly packed side chains in I-forms and S-forms would explain the differences in ANS binding. A compilation of the properties of I-forms and S-forms indicate that: (i) they have compact structures; (ii) they have secondary structures of the same type as native phage; (iii) they have non-native morphologies; and (iv) they may have nonrigid side chain packing. These are the properties of molten globules.
authors.affiliation: Department of Biochemistry and Biophysics, Washington State University, Pullman 99164.
authors.forename: A K
authors.initials: AK
authors.lastname: Dunker
authors.forename: L D
authors.initials: LD
authors.lastname: Ensign
authors.forename: G E
authors.initials: GE
authors.lastname: Arnold
authors.forename: L M
authors.initials: LM
authors.lastname: Roberts
mesh_terms: D000817:Anilino Naphthalenesulfonates / Q000737:chemistry; D001435:Bacteriophages / Q000502:physiology* / Q000648:ultrastructure; D002213:Capsid / Q000737:chemistry; D008854:Microscopy, Electron; D011487:Protein Conformation
chemical_list: D000817:Anilino Naphthalenesulfonates; C027132:1-anilino-8-naphthalenesulfonate