Bacteriophage phi YeO3-12, specific for Yersinia enterocolitica serotype O: 3, is related to coliphages T3 and T7

Bacteriophage phi YeO3-12 is a lytic phage of Yersinia enterocolitica serot ype O:3, The phage receptor is the lipopolysaccharide O chain of this serot ype that consists of the rare sugar 6-deoxy-L-altropyranose. A one-step gro wth curve of phi YeO3-12 revealed eclipse and latent periods of 15 and 25 m in, respectively, with a burst size of about 120 PFU per infected cell. In electron microscopy phi YeO3-12 virions showed pentagonal outlines, indicat ing their icosahedral nature. The phage capsid was shown to be composed of at least 10 structural proteins, of which a protein of 43 kDa was predomina nt. N-terminal sequences of three structural proteins were determined, two of them showing strong homology to structural proteins of coliphages T3 and T7, The phage genome was found to consist of a double-stranded DNA molecul e of 40 kb without cohesive ends. A physical map of the phage DNA was const ructed using five restriction enzymes, The phage infection could be effecti vely neutralized using serum from a rabbit immunized with whole phi YeO3-12 particles. The antiserum also neutralized T3 infection, although not as ef ficiently as that of phi YeO3-12. phi YeO3-12 was found to share, in additi on to the N-terminal sequence homology, several common features with T3, in cluding morphology and nonsubjectibility to F exclusion. The evidence concl usively indicated that phi YeO3-12 is the first close relative of phage T3 to be described.