RETRACTION
Volume 27, no. 6, p. 2144–2154, 2007, https://doi.org/10.1128/MCB.02347-06. We hereby retract this article. After publication, the article was found to have image duplications in Fig. 1, 2, 3, and 8, which represent a major deviation from established scientific standards for publication. We did not notice the duplications during submission. We have provided to the journal the raw data on which the paper is based. The raw data fully reflect the results and the conclusions presented in the paper. Therefore, we intend to submit a new manuscript that would address the problems that have occurred in the paper. The first author has assumed responsibility for the preparation of the figures. We apologize for this data misrepresentation.