Phage T4 SegB protein is a homing endonuclease required for the preferred inheritance of T4 tRNA gene region occurring in co-infection with a related phage.

ABSTRACT: Homing endonucleases initiate nonreciprocal transfer of DNA segments containing their own genes and the flanking sequences by cleaving the recipient DNA. Bacteriophage T4 segB gene, which is located in a cluster of tRNA genes, encodes a protein of unknown function, homologous to homing endonucleases of the GIY-YIG family. We demonstrate that SegB protein is a site-specific endonuclease, which produces mostly 3' 2-nt protruding ends at its DNA cleavage site. Analysis of SegB cleavage sites suggests that SegB recognizes a 27-bp sequence. It contains 11-bp conserved sequence, which corresponds to a conserved motif of tRNA TpsiC stem-loop, whereas the remainder of the recognition site is rather degenerate. T4-related phages T2L, RB1 and RB3 contain tRNA gene regions that are homologous to that

SUBMITTER: Brok-Volchanskaya VS 

PROVIDER: S-EPMC2330249 | biostudies-literature | 2008 Apr

REPOSITORIES: biostudies-literature