H. Iwasaki et al., Mutational analysis of the functional motifs of RuvB, an AAA(+) class helicase and motor protein for Holliday junction branch migration, MOL MICROB, 36(3), 2000, pp. 528-538
Escherichia coli RuvB protein, together with RuvA, promotes branch migratio
n of Holliday junctions during homologous recombination and recombination r
epair. The RuvB molecular motor is an intrinsic ATP-dependent DNA helicase
with a hexameric ring structure and its architecture has been suggested to
be related to those of the members of the AAA(+) protein class. In this stu
dy, we isolated a large number of plasmids carrying ruvB mutant genes and i
dentified amino acid residues important for the RuvB functions by examining
the in vivo DNA repair activities of the mutant proteins. Based on these m
utational studies and amino acid conservation among various RuvBs, we ident
ified 10 RuvB motifs that agreed well with the features of the AAA(+) prote
in class and that distinguished the primary structure of RuvB from that of
typical DNA/RNA helicases with seven conserved helicase motifs.