| | Predicted specificity1 |
|---|
DNA interaction | P22 gene | P22 | ε34 | ST64T | ST104 | Para-1 | Scho-1 |
|---|
DNA packaging |
3
| P22 | P22(96%) | P22(96%) | P22(96%) | P22(98%) | P22(99%) |
Integration2 |
int
| P22(98%) thrW |
ε
34
argU | P22(98%) thrW | P22(98%) thrW | P22(98%) thrW | P22(98%) thrW |
Early anti-termination |
24
| P22 |
ε
34,3
| P22(92%) | P22(98%) | P22(96%) | P22(93%) |
Prophage repressor |
c2
| P22 |
ε
34
| L(100%) | ST104 | ST104 (100%) | Scho1 |
DNA replication |
18
5
| P22 | λ (94%)5,7 | ST64T4 | HK97 (98%)7 | ST64T (97%)4 | λ (94%)5,7 |
Late anti-termination |
23
| λ (96%)6 | λ (99%) | Sf6(97%)7 | ST104 | λ (99%) | Sf6(96%) |
- 1. On each line, the table indicates (without parentheses) the experimentally-determined specificty according to the prototypical phage with that specificty. If two proteins have ≥ 92% amino acid sequence identity, the specificty is predicted to be the same, and the percent amino acid sequence identity to the prototypical protein is given in parentheses. If two unstudied proteins have <92% amino acid sequence identity their specificity is predicted to be different and one was arbitrarily chosen to be the prototype (e.g., ST64T DNA replication).
- 2. The tRNA gene into which phage integrates is shown below the int protein comparisons.
- 3. Has 72% overall amino acid sequence identity to its phage HK97 homologue, but amino acids 74–113 are very similar to the HK97 protein (see text).
- 4. Both have 82% amino acid sequence identity to its phage Sf6 homologue; it is not known if proteins with this level of difference could have the same target specificity.
- 5. N-terminal domain only (amino acids 1–162). The whole ε34 and Scho1 putative replication origin recognition proteins (ε34 gp50 and Scho1 gpSC0340, respectively) are 96% and 97% identical to the phage ES18 homologue [33]. Their N-terminal regions are 94% identical to phage λ gpO amino acids 17 through 148, and the N-terminal 162 amino acids have been shown to bind the origin [81].
- 6. Shown experimentally to have the same specificity as λ gpQ [82].
- 7. Phages Sf6, HK97 and λ do not infect Salmonella, but the indicated Salmonella phage protein is predicted to have the same specificity as one of these phages.
