title: Formation of a covalent complex between the terminal protein of pneumococcal bacteriophage Cp-1 and 5'-dAMP.
abstract: Incubation of extracts of Cp-1-infected Streptococcus pneumoniae with [alpha-32P]dATP produced a labeled treatment with micrococcal nuclease and sensitive to treatment with proteinase K. Incubation of the 32P-labeled protein with 5 M piperidine for 4 h at 50 degrees C released 5'-dAMP, indicating that a covalent complex between the terminal protein and 5'-dAMP was formed in vitro. When the four deoxynucleoside triphosphates were included in the reaction mixture, a labeled complex of slower electrophoretic mobility in sodium dodecyl sulfate-polyacrylamide gels than the terminal protein-dAMP complex was also found, indicating that the Cp-1 terminal protein-dAMP complex can be elongated and, therefore, that it is an initiation complex. Treatment of the 32P-labeled terminal protein-dAMP complex with 5.8 M HCl at 110 degrees C for 2 h yielded phosphothreonine. These results, together with the resistance of the terminal protein-DNA linkage to hydroxylamine, suggest that the Cp-1 terminal protein is covalently linked to the DNA through a phosphoester bond between L-threonine and 5'-dAMP, namely, a O-5'-deoxyadenylyl-L-threonine bond.
authors.forename: P
authors.initials: P
authors.lastname: García
authors.forename: J M
authors.initials: JM
authors.lastname: Hermoso
authors.forename: J A
authors.initials: JA
authors.lastname: García
authors.forename: E
authors.initials: E
authors.lastname: García
authors.forename: R
authors.initials: R
authors.lastname: López
authors.forename: M
authors.initials: M
authors.lastname: Salas
mesh_terms: D001435:Bacteriophages / Q000235:genetics* / Q000378:metabolism; D004261:DNA Replication; D004279:DNA, Viral / Q000096:biosynthesis; D004268:DNA-Binding Proteins / Q000378:metabolism*; D003838:Deoxyadenine Nucleotides / Q000378:metabolism*; D013296:Streptococcus pneumoniae; D013912:Threonine / Q000378:metabolism; D014764:Viral Proteins / Q000378:metabolism*; D014779:Virus Replication
chemical_list: D004279:DNA, Viral; D004268:DNA-Binding Proteins; D003838:Deoxyadenine Nucleotides; D014764:Viral Proteins; C048231:terminal protein, Streptococcus phage Cp-1; D013912:Threonine