title: In vitro packaging of individual genomic segments of bacteriophage phi 6 RNA: serial dependence relationships.
abstract: Bacteriophage phi 6 has a genome of three segments of double-stranded RNA enclosed in a procapsid composed of four different proteins. The preformed procapsid is capable of packaging plus-strand transcripts of the genomic segments in an in vitro reaction. The packaging of the three segments shows a strong order of dependence in that segment S packages alone, but segment M requires S and and segment L requires S and M for efficient packaging. Packaging of individual segments is dependent on unique packaging sequences of about 200 nucleotides near the 5' ends of the segments. Deletions that invade these regions destroy packaging competence for the particular segment and for the dependent segments as well. In the presence of 2 mM phosphate and at magnesium ion concentrations above 4 mM, packaging becomes progressively more independent and ultimately nonspecific with respect to phi 6 sequences.
authors.affiliation: Department of Microbiology, Public Health Research Institute, New York, New York 10016, USA.
authors.forename: X
authors.initials: X
authors.lastname: Qiao
authors.forename: G
authors.initials: G
authors.lastname: Casini
authors.forename: J
authors.initials: J
authors.lastname: Qiao
authors.forename: L
authors.initials: L
authors.lastname: Mindich
mesh_terms: D017126:Bacteriophage phi 6 / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development*; D002213:Capsid / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D004926:Escherichia coli / Q000821:virology; D016679:Genome, Viral; D008274:Magnesium / Q000494:pharmacology; D010957:Plasmids / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics; D015183:Restriction Mapping; D017384:Sequence Deletion
chemical_list: D018076:DNA, Complementary; D012367:RNA, Viral; D008274:Magnesium