Structural plasticity of 4-α-helical bundles exemplified by the puzzle-like molecular assembly of the Rop protein.

ABSTRACT: The dimeric Repressor of Primer (Rop) protein, a widely used model system for the study of coiled-coil 4-α-helical bundles, is characterized by a remarkable structural plasticity. Loop region mutations lead to a wide range of topologies, folding states, and altered physicochemical properties. A protein-folding study of Rop and several loop variants has identified specific residues and sequences that are linked to the observed structural plasticity. Apart from the native state, native-like and molten-globule states have been identified; these states are sensitive to reducing agents due to the formation of nonnative disulfide bridges. Pro residues in the loop are critical for the establishment of new topologies and molten globule states; their effects, however, can be in part compensated by

SUBMITTER: Amprazi M 

PROVIDER: S-EPMC4121800 | biostudies-literature | 2014 Jul

REPOSITORIES: biostudies-literature