Accessory factors determine the order of strand exchange in Xer recombination at psi.

Xer site-specific recombination in Escherichia coli converts plasmid multimers to monomers, thereby ensuring their correct segregation at cell division. Xer recombination at the psi site of plasmid pSC101 is preferentially intramolecular, giving products of a single topology. This intramolecular sel...

Full description

Bibliographic Details
Main Authors: Bregu, M, Sherratt, D, Colloms, S
Format: Journal article
Language:English
Published: 2002
_version_ 1797102502697500672
author Bregu, M
Sherratt, D
Colloms, S
author_facet Bregu, M
Sherratt, D
Colloms, S
author_sort Bregu, M
collection OXFORD
description Xer site-specific recombination in Escherichia coli converts plasmid multimers to monomers, thereby ensuring their correct segregation at cell division. Xer recombination at the psi site of plasmid pSC101 is preferentially intramolecular, giving products of a single topology. This intramolecular selectivity is imposed by accessory proteins, which bind at psi accessory sequences and activate Xer recombination at the psi core. Strand exchange proceeds sequentially within the psi core; XerC first exchanges top strands to produce Holliday junctions, then XerD exchanges bottom strands to give final products. In this study, recombination was analysed at sites in which the psi core was inverted with respect to the accessory sequences. A plasmid containing two inverted-core psi sites recombined with a reversed order of strand exchange, but with unchanged product topology. Thus the architecture of the synapse, formed by accessory proteins binding to accessory sequences, determines the order of strand exchange at psi. This finding has important implications for the way in which accessory proteins interact with the recombinases.
first_indexed 2024-03-07T06:06:52Z
format Journal article
id oxford-uuid:ee272af0-26f4-4667-bbf4-1611a213a58b
institution University of Oxford
language English
last_indexed 2024-03-07T06:06:52Z
publishDate 2002
record_format dspace
spelling oxford-uuid:ee272af0-26f4-4667-bbf4-1611a213a58b2022-03-27T11:30:33ZAccessory factors determine the order of strand exchange in Xer recombination at psi.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:ee272af0-26f4-4667-bbf4-1611a213a58bEnglishSymplectic Elements at Oxford2002Bregu, MSherratt, DColloms, SXer site-specific recombination in Escherichia coli converts plasmid multimers to monomers, thereby ensuring their correct segregation at cell division. Xer recombination at the psi site of plasmid pSC101 is preferentially intramolecular, giving products of a single topology. This intramolecular selectivity is imposed by accessory proteins, which bind at psi accessory sequences and activate Xer recombination at the psi core. Strand exchange proceeds sequentially within the psi core; XerC first exchanges top strands to produce Holliday junctions, then XerD exchanges bottom strands to give final products. In this study, recombination was analysed at sites in which the psi core was inverted with respect to the accessory sequences. A plasmid containing two inverted-core psi sites recombined with a reversed order of strand exchange, but with unchanged product topology. Thus the architecture of the synapse, formed by accessory proteins binding to accessory sequences, determines the order of strand exchange at psi. This finding has important implications for the way in which accessory proteins interact with the recombinases.
spellingShingle Bregu, M
Sherratt, D
Colloms, S
Accessory factors determine the order of strand exchange in Xer recombination at psi.
title Accessory factors determine the order of strand exchange in Xer recombination at psi.
title_full Accessory factors determine the order of strand exchange in Xer recombination at psi.
title_fullStr Accessory factors determine the order of strand exchange in Xer recombination at psi.
title_full_unstemmed Accessory factors determine the order of strand exchange in Xer recombination at psi.
title_short Accessory factors determine the order of strand exchange in Xer recombination at psi.
title_sort accessory factors determine the order of strand exchange in xer recombination at psi
work_keys_str_mv AT bregum accessoryfactorsdeterminetheorderofstrandexchangeinxerrecombinationatpsi
AT sherrattd accessoryfactorsdeterminetheorderofstrandexchangeinxerrecombinationatpsi
AT collomss accessoryfactorsdeterminetheorderofstrandexchangeinxerrecombinationatpsi