Enter o b ac ter i a ph a ge T 4 is a b ac ter io p ha ge t ha t in fe ct s E s cher ic hi a co li b act e ri a. Th e T 4 ph a ge is a member of the T-eve n ph a ge s, a g ro up inc lud in g ent er o b act er io p ha g es T 2 a nd T 6. T 4 is capable of un der go in g on ly a ly tic li fe c y c l e an d n ot th e lys og en ic li f e c y c l e. Th e T 4 ph a ges do u ble-st ra nd ed D N A ge no me is a bout 1 6 9 kb p long[1] an d en code s 2 8 9 pro t e ins. Th e T4 gen om e is termin a ll y re dun da n t a nd is first re p lic at ed as a un it, t hen sever al ge no mic un its a re rec om b in ed end-to-end to fo rm a co nc at e mer. When packaged, the concatemer is cut at unspecific positions of the same length, leading to several genomes that represent circular permutations of the original.[2] The T4 genome bears eukaryote-like intron sequences. Translation The Shine-Dalgarno sequence GAGG dominates in bacteriophage T4 early genes, whereas the sequence GGAG is a target for the T4 endonuclease RegB that initiates the early mRNA degradation.
Posted on: Sun, 28 Dec 2014 20:36:42 +0000
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