Protein
Serine recombinase gin
Organism
Escherichia phage D108
Function
Performs inversion of a viral segment (G-segment) that encodes two alternate pairs of tail fiber proteins thereby modifying the host specificity of the virus. Binds as a dimer to the viral gix sites which are 34-bp palindromic sequences that flank the invertible G-segment. Catalyzes site-specific recombination in the presence of the host factor Fis. Gin dimers bound to each of the gix sites and host factor Fis bound to the enhancer come together to form the synaptic complex. Each Gin monomer introduces a nick and becomes covalently attached to the 5'-phosphate of the DNA, resulting in double-stranded staggered breaks at both recombination sites. A 180 degrees rotation of one of the two Gin dimers followed by religation of the DNA leads to the inversion of the G-segment (By similarity).
Similarity
Belongs to the site-specific recombinase resolvase family.
Sequence
MLIGYVRVSTNDQNTDLQRNALVCAGCEQIFEDKLSGTRTDRPGLKRALKRLQKGDTLVVWKLDRLGRSMKHLISLVGELRERGINFRSLTDSIDTSSPMGRFFFHVMGALAEMERELIIERTMAGLAAARNKGRIGGRPPKLTKAEWEQAGRLLAQGIPRKQVALIYDVALSTLYKKHPAKRTHIENDDRINQIDR