Synapsis of Tn3 recombination sites: unpaired sites destabilize synapses by a partner exchange mechanism.
J Mol Biol
; 319(2): 385-93, 2002 May 31.
Article
em En
| MEDLINE
| ID: mdl-12051915
Catalysis of site-specific recombination is preceded by the formation of a synapse comprising two DNA sites and multiple subunits of the recombinase, together with other "accessory" proteins in some cases. We investigated the stability of synapses of Tn3 resolvase-bound res recombination sites, in plasmids containing either two or three res sites. Although synapses are long-lived in plasmids with just two res sites, persisting for tens of minutes, a synapse of any two sites is relatively short-lived in plasmids with three res sites. The three alternative pairwise synapses that can be formed in three-res plasmids re-assort rapidly relative to the rate of recombination. We propose a "partner exchange" mechanism for this re-assortment, involving direct attack on a synapse by an unpaired res site. This mechanism reconciles studies on selective synapsis in multi-res substrates, which imply rapid interchange of synaptic pairings, with studies indicating that synapses of two Tn3res sites are stable.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Plasmídeos
/
Recombinação Genética
/
Elementos de DNA Transponíveis
Idioma:
En
Ano de publicação:
2002
Tipo de documento:
Article