Evolution of RecA
Some interesting features of the evolution of RecA proteins:
- Arabidopsis thaliana encodes a nuclear gene for a RecA protein
that functions in the chloroplast and is evolutionarily related to cyanobacterial
RecA genes, suggesting that it was transfered to the nucleus of plants
sometime after the endosymbiosis with the chloroplast evolved.
- Many Mycobacterial species have inteins (protein introns which are
removed post-translationally) in their RecA proteins (see
al 2000 for review).
- Myxococcus xanthus encodes two RecAs genes (see Norioka
- Lactococcus lactis encodes an usual RecA-like protein on the
phage resistance plasmid pNP40. This gene is next to a UmuC-like gene.
The functions of these proteins are not well characterized.
- Spiroplasma citri has a recA-like gene but it only has
~390 bp similar to other recAs. S. melliferum encodes a complete
recA gene but it contains a stop codon early in the gene. Both species
are highly UV sensitive.
- The pea-aphid endosymbiont Buchnera aphidicola does not encode
a recA homolog in its complete genome (Shigenobu
et al, 2000)
Use of RecA as a phylogenetic marker:
and Sharp (1993) first addressed the possibility of using phylogenetic
analysis of recA genes as a tool to study bacterial evolutionary
- I followed up their analysis using the sequences of 40 additional recA
genes that have been entered into the databases through 1995. (Eisen,
1995). In this study I showed that RecA based phylogenies are very
similar to rRNA based phylogenies from the same species and that RecA trees
have similar powers of resolution. For more detail about this study see
Notes on Eisen 1995
- Tanja Gruber and I used RecA comparisons to examine the phylogeny of
species in the Chlorobium and Chloroflexus genera (Gruber
et al 1998) For more detail about this see Notes
on Gruber et al 1998.
- Advantages of using RecA as a phylogenetic marker for bacteria
- Relatively easy to clone for a protein encoding gene
- Conserved function among bacteria
- Sequence conservation varies across molecule
- Alignments are essentially unambiguous
- Sequence information can be helpful in creating recA- mutants
- 3D crystal structure of E. coli RecA available
- Disadvantages of using RecA as a phylogenetic marker for bacteria
- Multiple divergent genes in at least one species (M. xanthus)
- Number of sequences still 100 fold lower than for SS-rRNA
- Similarity to Archaeal and Eukaryotic proteins somewhat low
- Other studies using RecA sequences for phylogenetic or evolutionary
studies of bacteria
et al. Phylogeneetic analysis of bifidobacteria using recA
et al. 1995, Nowak
, et al. 1996. Genotyping of acinetobacters using recA PCR-RFLPs.
- Van Waasbergen et al. 1996. Abstracts of ASM 96: 404. Phylogeny of
deep subsurface Arthrobacter.
et al. recA sequences to study recombination and genetic exchange in
et al 2000 used recA sequences to study the population structure of
et al 2000 used analysis of RecA diversity within H. pylori
to study population structure
et al 2000 used analysis of RecA to study population structure of Neisseria
et al 2000 used analysis of RecA to study evolution of pathogenic Vibrios
et al 2000 used analysis of RecA for the identification of Mycobacterium
et al 2000 used phylogenetic analysis of RecA to study the relationships
of Frankia and Acidothermus
RecA-like genes in eukaryotes and Archaea
- Archaea: Sandler
et al. (1996) reported the cloning and characteriztion of RecA-like
genes from a variety of Archaea.
- Eukaryotes: Stassen
et al. (1997) studied the evolution of RecA-like proteins (Rad51, DMC1,
etc) in eukaryotes.
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