Published online 7 August 2006
Nucleic Acids Research, 2006, Vol. 34, No. 13 3731-3741
© 2006 The Author(s)
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.0/uk/) which permits unrestricted non-commerical use, distribution, and reproduction in any medium, provided the original work is properly cited.
Article |
Role of ATP hydrolysis in the DNA translocase activity of the bovine papillomavirus (BPV-1) E1 helicase
Institute for Cancer studies, University of Sheffield Beech Hill Road, Sheffield S10 2RX, UK
*To whom correspondence should be addressed. Tel: +44 114 2712482; Fax: +44 114 2713892; Email: c.m.sanders{at}sheffield.ac.uk
Received May 30, 2006. Revised July 10, 2006. Accepted July 17, 2006.
The E1 protein of bovine papillomavirus type-1 is the viral replication initiator protein and replicative helicase. Here we show that the C-terminal
300 amino acids of E1, that share homology with members of helicase superfamily 3 (SF3), can act as an autonomous helicase. E1 is monomeric in the absence of ATP but assembles into hexamers in the presence of ATP, single-stranded DNA (ssDNA) or both. A 16 base sequence is the minimum for efficient hexamerization, although the complex protects
30 bases from nuclease digestion, supporting the notion that the DNA is bound within the protein complex. In the absence of ATP, or in the presence of ADP or the nonhydrolysable ATP analogue AMPPNP, the interaction with short ssDNA oligonucleotides is exceptionally tight (T1/2 > 6 h). However, in the presence of ATP, the interaction with DNA is destabilized (T1/2
60 s). These results suggest that during the ATP hydrolysis cycle an internal DNA-binding site oscillates from a high to a low-affinity state, while proteinprotein interactions switch from low to high affinity. This reciprocal change in proteinprotein and proteinDNA affinities could be part of a mechanism for tethering the protein to its substrate while unidirectional movement along DNA proceeds.
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
C. M. Sanders, O. V. Kovalevskiy, D. Sizov, A. A. Lebedev, M. N. Isupov, and A. A. Antson Papillomavirus E1 helicase assembly maintains an asymmetric state in the absence of DNA and nucleotide cofactors Nucleic Acids Res., October 8, 2007; 35(19): 6451 - 6457. [Abstract] [Full Text] [PDF] |
||||
