Making sense of a gene fusion event in Proteobacteria

1
Making sense of a gene fusion event in
Proteobacteria

• Dawn Anderson (Berea College)
• Rob Barber (U of Wisconsin Parkside)
• Teresa Johnson (College of Wooster)

2
A promiscuous protein domain (and coding region)
The GAT-1 family is comprised of proteins
containing a Type-1 glutamine amidotransferase-lik
e domain. Proteins in this family display an
alpha/beta hydrolase fold with a nucleophilic
elbow. This transferase-like domain can
be present alone or as a fusion with several
other protein domains. A fusion between this
domain and an AraC DNA binding domain has been
found in prokaryotes.
3
Domain fusion to ArgF DNA binding domain
restricted to Proteobacteria
Mesorhizobium sp. Alpha proteobacteria
Sinorhizobium meliloti
Agrobacterium tumefaciens
Silicibacter sp.
Magnetospirillum magnetotacticum
Paracoccus denitrificans
Rhodobacter sphaeroides
Polaromonas sp. Beta proteobacteria
Chromobacterium violaceum
Ralstonia solanacearum
Ralstonia metallidurans
Ralstonia eutropha
Burkholderia vietnamiensis
Burkholderia pseudomallei
Azotobacter vinelandii Gamma proteobacteria
Photobacterium profundum
Chromohalobacter salexigens
Pseudomonas putida
Pseudomonas aeruginosa
Vibrio
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Phylogeny suggests divergence prior to speciation
5
N-terminal domain phylogeny
6
Gene associations/neighborhoods offer little
functional inference
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Approaches to test gene product function

• Clone gene, express and purify predicted gene
  product (trying heparin chromatography)
• Structure determination and model building
  exercises
• Gene expression experiments possible
  (microarrays, proteomics) but likely offer little
  insight due to prediction of regulatory role

8
FusionDB offered little insight regarding this
protein family