Bacteriophage P1 Ban protein is a hexameric DNA helicase that interacts with and substitutes for Escherichia coli DnaB.

ABSTRACT: Since the ban gene of bacteriophage P1 suppresses a number of conditionally lethal dnaB mutations in Escherichia coli, it was assumed that Ban protein is a DNA helicase (DnaB analogue) that can substitute for DnaB in the host replication machinery. We isolated and sequenced the ban gene, purified the product, and analysed the function of Ban protein in vitro and in vivo. Ban hydrolyses ATP, unwinds DNA and forms hexamers in the presence of ATP and magnesium ions. Since all existing conditionally lethal dnaB strains bear DnaB proteins that may interfere with the protein under study, we constructed a dnaB null strain by using a genetic set-up designed to provoke the conditional loss of the entire dnaB gene from E.coli cells. This novel tool was used to show that Ban restores the viability of

SUBMITTER: Lemonnier M 

PROVIDER: S-EPMC165978 | biostudies-literature | 2003 Jul

REPOSITORIES: biostudies-literature