Mechanism of DNA Translocation in a Replicative Hexameric Helicase

Journal Article · Sun Jan 01 04:00:00 EST 2006 · Nature

DOI:https://doi.org/10.1038/nature04943· OSTI ID:914349

Enemark, E; Joshua-Tor, L

The E1 protein of papillomavirus is a hexameric ring helicase belonging to the AAA + family. The mechanism that couples the ATP cycle to DNA translocation has been unclear. Here we present the crystal structure of the E1 hexamer with single-stranded DNA discretely bound within the hexamer channel and nucleotides at the subunit interfaces. This structure demonstrates that only one strand of DNA passes through the hexamer channel and that the DNA-binding hairpins of each subunit form a spiral 'staircase' that sequentially tracks the oligonucleotide backbone. Consecutively grouped ATP, ADP and apo configurations correlate with the height of the hairpin, suggesting a straightforward DNA translocation mechanism. Each subunit sequentially progresses through ATP, ADP and apo states while the associated DNA-binding hairpin travels from the top staircase position to the bottom, escorting one nucleotide of single-stranded DNA through the channel. These events permute sequentially around the ring from one subunit to the next.

• Research Organization: Brookhaven National Laboratory (BNL) National Synchrotron Light Source
• Sponsoring Organization: Doe - Office Of Science
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 914349
• Report Number(s): BNL--78917-2007-JA
• Journal Information: Nature, Journal Name: Nature Vol. 442
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRYSTAL STRUCTURE
DNA
NUCLEOTIDES
OLIGONUCLEOTIDES
PROTEINS
TRANSLOCATION
national synchrotron light source