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Plasmid partitioning and the spreading of P1 partition protein ParB
Author(s) -
Rodionov Oleg,
Yarmolinsky Michael
Publication year - 2004
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2004.04055.x
Subject(s) - biology , prophage , plasmid , centromere , genetics , low copy number , dna , mutant , partition (number theory) , chromosome , gene , bacteriophage , escherichia coli , mathematics , combinatorics
Summary Bacterial plasmids of low copy number, P1 prophage among them, are actively partitioned to nascent daughter cells. The process is typically mediated by a pair of plasmid‐encoded proteins and a cis ‐acting DNA site or cluster of sites, referred to as the plasmid centromere. P1 ParB protein, which binds to the P1 centromere ( parS ), can spread for several kilobases along flanking DNA. We argue that studies of mutant ParB that demonstrated a strong correlation between spreading capacity and the ability to engage in partitioning may be misleading, and describe here a critical test of the dependence of partitioning on the spreading of the wild‐type protein. Physical constraints imposed on the spreading of P1 ParB were found to have only a minor, but reproducible, effect on partitioning. We conclude that, whereas extensive ParB spreading is not required for partitioning, spreading may have an auxiliary role in the process.