Preferential orientation of natural lambdoid prophages and bacterial chromosome organization.

All known lambdoid prophages of Escherichia coli have the same orientation with respect to direction of chromosomal replication. This includes 12 prophages that are replicated in one direction and five in the other. Among candidate explanations, the most amenable to experimental study is an effect on dif site function in assuring chromosomal segregation. This is but one of numerous examples of strand bias in the E. coli genome, all of which may interact with one another. Copyright 2002 Elsevier Science (USA)