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

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 th...

Full description

Saved in:

Bibliographic Details
Published in:	Nucleic acids research Vol. 31; no. 14; pp. 3918 - 3928
Main Authors:	Lemonnier, Marc, Ziegelin, Günter, Reick, Tobias, Gómez, Ana Muñoz, Díaz‐Orejas, Ramón, Lanka, Erich
Format:	Journal Article
Language:	English
Published:	England Oxford University Press 15-07-2003 Oxford Publishing Limited (England)
Subjects:	Amino Acid Sequence Bacterial Proteins Bacteriophage P1 - enzymology Bacteriophage P1 - genetics Dimerization DNA Helicases - genetics DNA Helicases - metabolism DNA, Viral - chemistry DNA, Viral - genetics DnaB Helicases Escherichia coli - enzymology Escherichia coli - genetics Escherichia coli - growth & development Genetic Complementation Test Molecular Sequence Data Mutation Protein Binding Sequence Alignment Sequence Analysis, DNA Sequence Homology, Amino Acid Viral Proteins - chemistry Viral Proteins - genetics Viral Proteins - isolation & purification Viral Proteins - metabolism
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	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 cells that completely lack DnaB at 30°C, but not at 42°C. Surprisingly, growth was restored by the dnaB252 mutation at a temperature that is restrictive for ban and dnaB252 taken separately. This indicates that Ban and DnaB are able to interact in vivo. Complementary to these results, we demonstrate the formation of DnaB–Ban hetero‐oligomers in vitro by ion exchange chromatography. We discuss the interaction of bacterial proteins and their phage‐encoded analogues to fulfil functions that are essential to phage and host growth.
Bibliography:	Received as resubmission April 20, 2003; Accepted May 15, 2003 istex:8DBD454EE4F9A184C6A8FAEF029DA0D361B63DD4 local:gkg463 To whom correspondence should be addressed. Tel: +34 91 564 4562; Fax: +34 91 562 7518; Email: mlm@cib.csic.es ark:/67375/HXZ-SW1CBWHP-L ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2
ISSN:	0305-1048 1362-4962 1362-4962
DOI:	10.1093/nar/gkg463