Taking a molecular motor for a spin: helicase mechanism studied by spin labeling and PELDOR.

ABSTRACT: The complex molecular motions central to the functions of helicases have long attracted attention. Protein crystallography has provided transformative insights into these dynamic conformational changes, however important questions about the true nature of helicase configurations during the catalytic cycle remain. Using pulsed EPR (PELDOR or DEER) to measure interdomain distances in solution, we have examined two representative helicases: PcrA from superfamily 1 and XPD from superfamily 2. The data show that PcrA is a dynamic structure with domain movements that correlate with particular functional states, confirming and extending the information gleaned from crystal structures and other techniques. XPD in contrast is shown to be a rigid protein with almost no conformational changes resulti

SUBMITTER: Constantinescu-Aruxandei D 

PROVIDER: S-EPMC4737156 | biostudies-literature | 2016 Jan

REPOSITORIES: biostudies-literature