PROCESSES AT THE NICK REGION LINK CONJUGATION, T-DNA TRANSFER AND ROLLING CIRCLE REPLICATION

Citation
Vl. Waters et Dg. Guiney, PROCESSES AT THE NICK REGION LINK CONJUGATION, T-DNA TRANSFER AND ROLLING CIRCLE REPLICATION, Molecular microbiology, 9(6), 1993, pp. 1123-1130
Citations number
75
Language
INGLESE
art.tipo
Review
Categorie Soggetti
Biology,Microbiology
Journal title
ISSN journal
0950-382X
Volume
9
Issue
6
Year of publication
1993
Pages
1123 - 1130
Database
ISI
SICI code
0950-382X(1993)9:6<1123:PATNRL>2.0.ZU;2-X
Abstract
Data from prokaryotic replicative and conjugative systems, which inter relate DNA processing events initiated by a site-specific nick, are re viewed. While the replicative systems have been established in accorda nce with the rolling circle replication model, the mechanism of conjug ative replication has not been elucidated experimentally. We summarize data involving random point mutagenesis of the RK2 transfer origin (o riT), which yielded relaxation-deficient and transfer-deficient deriva tives having mutations exclusively in a 10bp region defined as the nic k region. Features of the RK2 (IncP) nick region, including the DNA se quence, nick site position, and 5' covalent attachment of the nicking protein, have striking parallels in other systems involving nicking an d mobilization of single-stranded DNA from a supercoiled substrate. Th ese other systems include T-DNA transfer occurring in Agrobacterium tu mefaciens Ti plasmid-mediated tumorigenesis in plants, and the rolling circle replication of plasmids of Gram-positive bacteria and of phiX1 74-like bacteriophage. The structural and functional similarities sugg est that IncP conjugative replication, originating at the oriT, and T- DNA transfer replication, originating at the T-DNA border, produce con tinuous strands via a rolling circle-type replication.