Distinct Streptococcus thermophilus bacteriophages share an extremely conserved DNA fragment.
A cross-hybridizing 2.2-kb EcoRI fragment was cloned from two lytic Streptococcus thermophilus bacteriophages with distinct phenotypes. The DNA fragments, which contained two unidentified open reading frames, differed at only 3 of 2207 nucleotide positions. Partial sequencing of a temperate S. thermophilus phage and of a further lytic phage belonging to a different lytic group isolated 20 years earlier from a different geographical area confirmed this extreme sequence conservation. Hybridization of this phage DNA with bacterial host DNA was not observed. The evolutionary implications of these observations are briefly discussed.
Brüssow
H
H
Nestlé Research Centre, Nestec Ltd., Vers-chez-les-Blanc, Lausanne, Switzerland.
Probst
A
A
Frémont
M
M
Sidoti
J
J
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017124:Conserved Sequence; D004279:DNA, Viral / Q000235:genetics*; D008892:Milk / Q000382:microbiology*; D008969:Molecular Sequence Data; D017108:Streptococcus Phages / Q000145:classification* / Q000235:genetics* / Q000254:growth & development
D004279:DNA, Viral