Abstract:
:The cer-Xer dimer resolution system of plasmid ColE1 is highly selective, acting only at sites on the same molecule and in direct repeat. Recombination requires the XerCD recombinase and accessory proteins ArgR and PepA. The Escherichia coli chromosome dimer resolution site dif and the type II hybrid site use the same recombinase but are independent of ArgR and PepA and show no site selectivity. This has led to the proposal that ArgR and PepA are responsible for the imposition of constraint. We describe here the characterization of a novel class of "conditionally constrained' multimer resolution sites whose properties support this hypothesis. In the presence of ArgR and PepA, plasmids containing conditionally constrained sites are monomeric, but in their absence, extensive multimerisation is seen. A mutant ArgR derivative (ArgR110), which is defective in cer-mediated dimer resolution, remains able to prevent plasmid multimerisation by a conditionally constrained site. This implies that the accessory factors block recombination in trans rather than ensuring rapid multimer resolution. When the distance between the ArgR and XerCD binding sites in a conditionally constrained site was altered by a non-integral number of helical turns, the site became unconstrained. Constraint was restored by the insertion of a full helical turn.
journal_name
Mol Microbioljournal_title
Molecular microbiologyauthors
Guhathakurta A,Viney I,Summers Ddoi
10.1046/j.1365-2958.1996.5471072.xsubject
Has Abstractpub_date
1996-05-01 00:00:00pages
613-20issue
3eissn
0950-382Xissn
1365-2958journal_volume
20pub_type
杂志文章abstract::Recently, sexual development in the heterothallic ascomycete Trichoderma reesei (anamorph of Hypocrea jecorina) has been achieved and thus initiated attempts to elucidate regulation and determinants of this process. While the α-type pheromone of this fungus fits the consensus known from other fungi, the assumed a-type...
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pub_type: 评论,杂志文章
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更新日期:2001-02-01 00:00:00
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pub_type: 杂志文章
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更新日期:2009-12-01 00:00:00
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pub_type: 杂志文章
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更新日期:2005-12-01 00:00:00
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journal_title:Molecular microbiology
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更新日期:1991-07-01 00:00:00
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pub_type: 杂志文章
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更新日期:2011-08-01 00:00:00