Synchrotron protein footprinting supports substrate translocation by ClpA via ATP-induced movements of the D2 loop.

ABSTRACT: Synchrotron X-ray protein footprinting is used to study structural changes upon formation of the ClpA hexamer. Comparative solvent accessibilities between ClpA monomer and ClpA hexamer samples are in agreement throughout most of the sequence, with calculations based on two previously proposed hexameric models. The data differ substantially from the proposed models in two parts of the structure: the D1 sensor 1 domain and the D2 loop region. The results suggest that these two regions can access alternate conformations in which their solvent protection is greater than that in the structural models based on crystallographic data. In combination with previously reported structural data, the footprinting data provide support for a revised model in which the D2 loop contacts the D1 sensor 1 doma

SUBMITTER: Bohon J 

PROVIDER: S-EPMC2929679 | biostudies-literature | 2008 Aug

REPOSITORIES: biostudies-literature