This article refers to:
RETRACTION
Vol. 29, no. 1, p. 83–92, 2009. The authors and the journal hereby retract this article. After publication, this article was found to have multiple images that were unacceptably manipulated (Fig. 2E, 3A and D, 4B, and 6), a clear violation of ASM's ethical standards. Since the integrity of the data as presented was compromised, this publication is retracted in its entirety. We apologize to the readers of Molecular and Cellular Biology and regret any inconvenience this causes. H. Kitagawa did not agree to this retraction.