How directional translocation is regulated in a DNA helicase motor.

ABSTRACT: PcrA helicase from Bacillus stearothermophilus is one of the smallest motor proteins structurally known in full atomic detail. It translocates progressively from the 3' end to the 5' end of single-stranded DNA utilizing the free energy from ATP hydrolysis. The similarities in structure and reaction pathway between PcrA helicase and F1-ATPase suggest a similar mechanochemical mechanism at work in both systems. Previous studies of PcrA translocation demonstrated a domain stepping mechanism in which, during one ATP hydrolysis cycle, the pulling together and pushing apart of two translocation domains is synchronized with alternating mobilities of the individual domains such that PcrA moves unidirectionally along single-stranded DNA. To substantiate this translocation mechanism, this study appl

SUBMITTER: Yu J 

PROVIDER: S-EPMC2084242 | biostudies-literature | 2007 Dec

REPOSITORIES: biostudies-literature