ClpX and MuB interact with overlapping regions of Mu transposase: implications for control of the transposition pathway

Genes Dev. 1997 Jun 15;11(12):1561-72. doi: 10.1101/gad.11.12.1561.

Abstract

Transposition of phage Mu is catalyzed by an extremely stable transposase-DNA complex. Once recombination is complete, the Escherichia coli ClpX protein, a member of the Clp/Hsp100 chaperone family, initiates disassembly of the complex for phage DNA replication to commence. To understand how the transition between recombination and replication is controlled, we investigated how transposase-DNA complexes are recognized by ClpX. We find that a 10-amino-acid peptide from the carboxy-terminal domain of transposase is required for its recognition by ClpX. This short, positively charged peptide is also sufficient to convert a heterologous protein into a ClpX substrate. The region of transposase that interacts with the transposition activator, MuB protein, is also defined further and found to overlap with that recognized by ClpX. As a consequence, MuB inhibits disassembly of several transposase-DNA complexes that are intermediates in recombination. This ability of MuB to block access to transposase suggests a mechanism for restricting ClpX-mediated remodeling to the proper stage during replicative transposition. We propose that overlap of sequences involved in subunit interactions and those that target a protein for remodeling or destruction may be a useful design for proteins that function in pathways where remodeling or degradation must be regulated.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • ATPases Associated with Diverse Cellular Activities
  • Adenosine Triphosphatases / metabolism*
  • Amino Acid Sequence
  • Bacteriophage mu / genetics
  • Bacteriophage mu / physiology*
  • Binding Sites
  • DNA Nucleotidyltransferases / chemistry*
  • DNA Nucleotidyltransferases / metabolism*
  • DNA-Binding Proteins / metabolism*
  • Endopeptidase Clp
  • Escherichia coli / enzymology
  • Escherichia coli / genetics
  • Escherichia coli / virology*
  • Escherichia coli Proteins
  • Kinetics
  • Models, Structural
  • Molecular Chaperones
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Polymerase Chain Reaction
  • Recombinant Proteins / metabolism
  • Recombination, Genetic
  • Transposases
  • Viral Proteins / metabolism*

Substances

  • DNA-Binding Proteins
  • Escherichia coli Proteins
  • Molecular Chaperones
  • MuB protein, Enterobacteria phage Mu
  • Recombinant Proteins
  • Viral Proteins
  • DNA Nucleotidyltransferases
  • Transposases
  • Endopeptidase Clp
  • Adenosine Triphosphatases
  • ClpX protein, E coli
  • ATPases Associated with Diverse Cellular Activities