POSTERS - BLAST X - University of Utah
POSTERS - BLAST X - University of Utah
POSTERS - BLAST X - University of Utah
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<strong>BLAST</strong> X Poster #14<br />
FUNCTIONAL ANALYSIS OF A LARGE NON-CONSERVED REGION OF FlgK (HAP1) FROM<br />
RHODOBACTER SPHAEROIDES<br />
Castillo, D.J., Ballado, T., Camarena, L., Dreyfus, G.<br />
Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional<br />
Autónoma de México, Apdo. Postal 70-243 Cd. Universitaria, 04510, Mexico, D.F., Mexico.<br />
The single subpolar flagellum <strong>of</strong> Rhodobacter sphaeroides shows an enlarged hookfilamentjunction.<br />
One <strong>of</strong> the two proteins that compose this section <strong>of</strong> the filament is HAP1Rs<br />
(FlgKRs) it contains a central non-conserved region <strong>of</strong> 860 amino acids that makes this protein<br />
about three times larger than its homologue in Salmonella enterica serovar Typhimurium. We<br />
investigated the role <strong>of</strong> this central portion <strong>of</strong> the unusually large HAP1 protein <strong>of</strong> R.<br />
sphaeroides by monitoring the effects <strong>of</strong> serial deletions in flgKRs, the gene encoding HAP1Rs,<br />
on swimming and swarming. Two deletion mutants did not assemble functional flagella, two<br />
were paralyzed and five exhibited reduced free-swimming speeds. Some mutants produced<br />
unusual swarming patterns on s<strong>of</strong>t agar without or with Ficoll 400. A segment <strong>of</strong> approximately<br />
200-aa <strong>of</strong> the central region <strong>of</strong> HAP1Rs that aligns with the variable region <strong>of</strong> the flagellin<br />
sequence from other γ- and β-proteobacteria was also found. Therefore, it is possible that the<br />
origin <strong>of</strong> this large central domain <strong>of</strong> HAP1Rs could be associated with an event <strong>of</strong> horizontal<br />
transfer and subsequent duplications and/or insertions.<br />
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