1. Red Tides

2. Marine Organisms
Trichodesmium erythraeum

3. Microscopic view Present in the form of colonies
Responsible for increased nitrogen fixation in the presence of Iron.

4. Analysis of possible regulatory motifs
Fe2+/Zn2+ uptake regulation proteins (FUR)
Bacterioferritin ( cytochrome b1)
ABC-type Fe3+ transport system periplasmic component
9 known proteins known for iron regulation

5. Upstream Sequences of Iron regulatory proteins
1) Periplasmic protein upstream sequence
2) Bacterioferritin upstream sequence
3) FUR upstream sequence
T T T T A C T T C A C G G G T C A A G A T T T T T T C T C T C T C C C T T T T C
C T T T T C T T C C T A A A T T C G G A C A T T T T A T C A C T C C T T A T A G
C T T T T A A C C C A A G A T T G A G G T G A T T T G A T T T C C C T T T T T C
A & T rich sequence
What about similar genes in other organisms ?

6. Upstream sequences of orthologs with similar motifs
Organism Gene Position Upstream Sequence
Anabaena A7120.all T C T T T C A A G A A C T T C C T C A A G G C G A A C A C C T G A G T G C A G A A G A T T T A T A T
Trichodesmium e. Tery.Te? T T T T T C A A A A C C T G C C A A A A G G C A A T C A T C T G A G T G C C G A A G A T C T T T A T
Synechococcus e. S7942.ser T C T T T C A A A A T C T C C C A G C A G G T G A A C A C C T C A G T G C T G A G G A C C T T T A C
Anabaena v. A29413.Av? T C T T T C A A G A A C T T C C T C A A G G C G A A C A C C T G A G C G C A G A A G A T T T A T A T
Nostoc p. S6803.sll T T T T T C A A A A T T T G C C G G A G G G G G A A C A T C T C A G T G C C G A G G A G T T A C A C
Thermosynechococcus e. TeBP1.tll T T T T C C A G A A T C T G C C T A A G G G C A A T C A C C T G A G T G C T G A A G A C C T C T A C
Crocosphaera w. Cwat.Cw? T A C T T C A T G C T C A A C A A G T G G G A G A A A T T T T G A C T G G T T T A G A A G G C C A T
Anabaena A7120.all T A C T C C A T G C T C A A C A A G T A G G A G A A A T T C T C A C A G G T T T A G A T G G A C A T
Anabaena v. A29413.Av? T A C T T C A T G C C C A A C A A G T G G G A G A A A T T C T C A C A G G A T T A G A T G G A C A T
Crocosphaera w. Cwat.Cw? TC T T C C A A A A T C T C C C T A G G G G G A A T C A T T T G A G T G C T G A G G A A T T G T T T
Nostoc p Npun.NpF T A C T T C A T G C T G A A C A A G T A G G A G A A A T T C T T A C C G G T T T A G A T G G G C A T
Trichodesmium e. Tery.Te? T A C T T C A T G C T C A A C A A G C A G G A G A A A T A T T A A C A G G T T T A G A A G G T C A T
Gloeobacter v Gvi.glr T G T T C C A G G A G T T G C C G G A G G G C A A T C A C C T C A A T G C C G A G G A G C T G C A C
Prochlorococcus m. PMED4.PMM T A T T T G A G A A T A T T G G A G C A G G T A A T C A T T T A A G T G C G G A A G A A G T T C A T

7. What can we conclude from the information ?
Matches with 2 Trichodesmium genes
Already knew………
Matches with 2 nostoc and 4 anabaena genes…… not a surprise….. Both are rich in A and T nucleotides……
What are other matches ?

8. Other matches ? Synechococcus e. Thermosynechococcus e.
Crocosphaera w. (2 – Genes)
Gloeobacter v.
Prochlorococcus m.
Iron regulatory upstream sequences somewhat similar to Trichodesmium………
Where else can we look for such matches ?

9. Finding FE+ regulatory genes ?
Intergenic sequences in the genome of Trichodesmium
Orthologs of the other promising iron regulatory genes in Trichodesmium.

10. Thanks To : Dr. Jeff Elhai Bioinformatics VCU
Presented by : Sukalpa Dutta