Virus grows tube to insert DNA during infection then sheds it

Researchers have discovered a tube-shaped structure that forms temporarily in a certain type of virus to deliver its DNA during the infection process and then dissolves after its job is completed. The researchers discovered the mechanism in the phiX174 virus, which attacks E. coli bacteria. The virus, called a bacteriophage because it infects bacteria, is in a class of viruses that do not contain an obvious tail section for the transfer of its DNA into host cells. “But, lo and behold, it appears to make its own tail,” said Michael Rossmann, Purdue University’s Hanley Distinguished Professor of Biological Sciences. “It doesn’t carry its tail around with it, but when it is about to infect the host it makes a tail.” Researchers were surprised to discover the short-lived tail. “This structure was completely unexpected,” said Bentley A. Fane, a professor in the BIO5 Institute at the University of Arizona. “No one had seen it before...