DNA Replication: A Cluster Linking a Hypothetical to the ruvABC Genes
Here is a short description of the function of the ruvABC genes
and the rolw they play in replication (from
Comparative and Evolutionary Analysis of the Bacterial Homologous Recombination Systems
by Rocha, Cornet, and Michel):
In E. coli, the joint molecules formed by RecA are resolved by either
the RuvABC complex or, in an unknown way, by the action of the RecG
helicase. The RuvAB and RuvC proteins catalyze the branch migration
and the resolution of Holliday junction recombination intermediates,
respectively. These three proteins are thought to interact in a
resolvasome complex, in which a RuvABC-junction complex tracks along
DNA, with RuvC able to scan for cleavable sequences as the DNA passes
through.
Now, look at the following cluster. Note
that
- the green genes numbered 2 encode Holliday junction DNA
helicase RuvA,
- the blue genes numbered 3 encode Holliday junction DNA
helicase RuvB,
- the purple genes numbered 4 encode Crossover junction
endodeoxyribonuclease ruvC (EC 3.1.22.4).
Look at the co-occurrences of these three genes with the red genes
numbered 1. It is clear that this uncharacterized gene
numbered 1 is closely related to the ruvABC genes.
Note that in E.coli the three ruvABC genes do not occur in a
single operon -- an inserted gene has separated ruvC from ruvAB.
Since the gene we are considering remains close to ruvC and the two
genes tend to be adjacent in many genomes, I would be tempted to
conjecture that the red genes play a role closely related to
ruvC.
That may be reaching too far.