Gene Ontology annotation based on Enzyme Commission mapping
Gene Ontology annotation based on UniProtKB/Swiss-Prot keyword mapping
Automatic Gene Ontology annotation based on Rhea mapping
Combined Automated Annotation using Multiple IEA Methods
Bacteriophage P4 DNA replication. Nucleotide sequence of the P4 replication gene and the cis replication region.
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Sequenced the P4 alpha replication gene encoding the 777-amino-acid (84,841 Da) gpAlpha protein and the adjacent cis replication region (crr).
"This segment of DNA contains two open reading frames of 106 and 777 amino acid residues; the latter of which is the coding sequence for the Mr 84,841 alpha protein, which is necessary for P4 DNA replication and is thought to act as a P4-specific DNA primase."
A common sequence motif, -E-G-Y-A-T-A-, identified within the primase domains of plasmid-encoded I- and P-type DNA primases and the alpha protein of the Escherichia coli satellite phage P4.
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Identified the conserved -E-G-Y-A-T-A- catalytic motif in the N-terminal primase domain of gpAlpha and showed that point mutations in this motif abolish primase activity and P4 DNA replication.
"The P4 alpha gene product, required for initiation of phage DNA replication, exhibits primase activity on single-stranded circular DNA templates."
Phage P4 alpha protein is multifunctional with origin recognition, helicase and primase activities.
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Demonstrated that purified gpAlpha combines origin/crr-specific DNA binding, NTP-dependent DNA helicase, and RNA-primer-synthesizing DNA primase activities in a single polypeptide.
"alpha Protein of satellite phage P4 of Escherichia coli is multifunctional in P4 replication with three activities. First, the protein (subunit M(r) = 84,900) complexes specifically the P4 origin and the cis replication region required for replication."
Phage P4 origin-binding domain structure reveals a mechanism for regulation of DNA-binding activity by homo- and heterodimerization of winged helix proteins.
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Solved the NMR structure of the C-terminal winged-helix origin-binding domain of gpAlpha (P4-OBD) and showed how Cnr binding regulates origin recognition.
"The origin-binding domain of the gpalpha protein of phage P4 (P4-OBD) mediates origin recognition and regulation of gpalpha activity by the protein Cnr."