The phi 80 and P22 attachment sites. Primary structure and interaction with Escherichia coli integration host factor.

摘要: Although the lambdoid bacteriophage phi 80 and P22 possess site-specific recombination systems analogous to lambda, they have different attachment (att) site specificities. We identified determined nucleotide sequences of att sites examined interaction these with purified Escherichia coli integration host factor (IHF). The sizes homologous core regions vary greatly: has a 46-base pair core, while lambda 17- 15-base cores, respectively. three phage show no significant homology, although dispersed homology in arm indicate that are related. All high A + T composition, restriction fragments carrying migrate anomalously upon polyacrylamide gel electrophoresis. IHF binds left common (attP) right attP attB (the bacterial site). In system, interacts on (designated H1, H2, H') none (Craig N., Nash, H.A. (1984) Cell 39, 707-716). Alignment all results consensus sequence for binding, Pyr-AANNNNTTGATAT. Among phage, number differs; however, location orientation binding relation respective well conserved. An H2 is present both attP, H' attP. This conservation suggests plays very similar role pathways flanking necessary function, as case function. These structural similarities presumably reflect mechanism phage.