Papillomavirus E1 helicase assembly maintains an asymmetric state in the absence of DNA and nucleotide cofactors

摘要: Concerted, stochastic and sequential mechanisms of action have been proposed for different hexameric AAA+ molecular motors. Here we report the crystal structure E1 helicase from bovine papillomavirus, where asymmetric assembly is first time observed in absence nucleotide cofactors DNA. Surprisingly, ATP-binding sites adopt specific conformations linked to positional changes DNA-binding hairpins, which follow a wave-like trajectory, as previously E1/DNA/ADP complex. The protein's thus maintains such an state DNA cofactors, allowing consideration propagation conformational wave around protein ring. data imply that wave's within domains not necessarily coupled with strictly hydrolysis ATP. Since single ATP event would affect whole hexamer, events may simply serve rectify direction motion.