MicrobiologyA universal protein-protein interaction motif in the eubacterialDNA replication and repair systems
(2001)
Journal - PNAS
Abstract :
Commonwealth Scientific and Industrial Research
Organisation Livestock Industries, 120 Meiers Road, Indooroopilly QLD
4068, Australia; and Research School of Chemistry,
Australian National University, Canberra ACT 0200, Australia
Communicated by W. James Peacock, Commonwealth Scientific and
Industrial Research Organisation, Canberra, Australia, July 24, 2001 (received for review March 9, 2001)
The interaction between DNA polymerases and sliding clamp proteins
confers processivity in DNA synthesis. This interactionis critical for
most DNA replication machines from viruses andprokaryotes to higher
eukaryotes. The clamp proteins also participatein a variety of dynamic
and competing protein-protein interactions.However, clamp-protein
binding sequences have not so far beenidentified in the eubacteria.
Here we show from three lines ofevidence, bioinformatics, yeast
two-hybrid analysis, and inhibitionof protein-protein interaction by
modified peptides, that variantsof a pentapeptide motif (consensus
QL[SD]LF) are sufficient toenable interaction of a number of
proteins with an archetypaleubacterial sliding clamp (the subunit
of Escherichia coli DNApolymerase III holoenzyme).
Representatives of this motif arepresent in most sequenced members of
the eubacterial DnaE, PolC,PolB, DinB, and UmuC families of DNA
polymerases and the MutS1mismatch repair protein family. The component
tripeptide DLF inhibitsthe binding of the (DnaE) subunit of
E. coli DNA polymeraseIII to at µM concentration,
identifying key residues. Comparisonof the eubacterial, eukaryotic,
and archaeal sliding clamp bindingmotifs suggests that the basic
interactions have been conservedacross the evolutionarylandscape.