Gene Ontology annotation based on Enzyme Commission mapping
Gene Ontology annotation based on UniProtKB/Swiss-Prot keyword mapping
Bacteriophage lambda; abortive infection of bacteria lysogenic for phage P2.
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Demonstrated that P2 lysogens abort bacteriophage lambda infection with an efficiency of plating below 10^-6 via the gene product that also kills recB and recC host mutants.
"The efficiency of plating of wild-type lambda on a host lysogenic for P2 is less than 10(-6), and only a small number of infected cells produce progeny phage. ... The P2 gene product responsible for preventing lambda growth also kills recombination-deficient bacteria of the recB and recC classes under conditions where P2 does not normally kill the host."
The P2 phage old gene: sequence, transcription and translational control.
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Determined the nucleotide sequence of the P2 old gene (encoding a 583-amino-acid protein) responsible for killing recB/recC mutants and interfering with phage lambda growth.
"The old (overcoming lysogenization defect) gene product of bacteriophage P2 kills Escherichia coli recB and recC mutants and interferes with phage lambda growth"
The old exonuclease of bacteriophage P2.
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Purified P2 Old as an MBP fusion protein and demonstrated processive 5'-to-3' exonuclease activity on dsDNA as well as nuclease activity on ssDNA and RNA releasing 5'-phosphoryl mononucleotides.
"The Old protein fused to maltose-binding protein has exonuclease activity on double-stranded DNA as well as nuclease activity on single-stranded DNA and RNA. The direction of digestion of double-stranded DNA is from 5' to 3', and digestion initiates at either the 5'-phosphoryl or 5'-hydroxyl terminus. The nuclease is active on nicked circular DNA, degrades DNA in a processive manner, and releases 5'-phosphoryl mononucleotides."
The full-length structure of Thermus scotoductus OLD defines the ATP hydrolysis properties and catalytic mechanism of Class 1 OLD family nucleases.
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Defined the ABC ATPase and Toprim two-metal-ion nuclease catalytic residues of P2 Old and proved that both ATP hydrolysis and DNA cleavage are essential for P2 Old-mediated lethality in recBC-deficient E. coli.
"We also demonstrate that mutants perturbing ATP hydrolysis or DNA cleavage in vitro impair P2 OLD-mediated killing of recBC-Escherichia coli hosts, indicating that both the ATPase and nuclease activities are required for OLD function in vivo."
UniProtKB record for P13520 (OLD_BPP2)
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Summarizes the EC 3.1.11.3 classification, Toprim domain, and antiphage interference properties of P2 Old.
"FUNCTION: An exonuclease that acts preferentially on linear dsDNA, processively degrading it from 5'-3', releasing 5'- phosphomononucleotides. Initiates on 5'-phosphate and 5'-hydroxyl ends. Also acts on linear ssDNA, nicked DNA and RNA. ATP enhances but is not necessary for exonuclease activity; has ATPase activity that is not stimulated by DNA (PubMed:7836278)."