Gene Ontology annotation based on InterPro domain architecture
Gene Ontology annotation based on UniProtKB/Swiss-Prot keyword mapping
Deep research summary for Bacteriophage T4 stp
-
Stp is a 26-amino-acid effector/regulator peptide rather than a catalytic nuclease.
"Stp itself is best understood as an **effector/regulator peptide**, not as the catalytic nuclease."
-
Stp selectively abolishes EcoPrrI DNA restriction activity without inhibiting its methyltransferase activity, which in turn unmasks the latent host PrrC anticodon nuclease.
"Penner et al. show that Stp **abolishes EcoPrrI restriction activity but not the cognate modification activity**, consistent with selective interference with the restriction apparatus"
UniProtKB entry P62765 (STP_BPT4)
-
Stp inactivates host DNA restriction systems including EcoPrrI and EcoR124I and consequently activates the host anticodon nuclease PrrC.
"Plays a role in the inactivation of several host DNA restriction systems including EcoprrI or EcoR124I. As a consequence, it activates the host anticodon nuclease PrrC. However, the phage-encoded RNA repair enzymes normally offset the damage. {ECO:0000269|PubMed:14507369, ECO:0000269|PubMed:1639077, ECO:0000269|PubMed:7791212}."
-
The conserved N-proximal 18 residues of Stp mediate both anti-restriction and PrrC activation.
"The conserved N-proximal 18 residue region of Stp is critical both for its anti-DNA restriction and ACNase activating functions. {ECO:0000269|PubMed:7791212}."