(Below N is a link to NCBI taxonomic web page and E link to ESTHER at designed phylum.) > cellular organisms: NE > Bacteria: NE > unclassified Bacteria: NE > unclassified Bacteria (miscellaneous): NE > bacterium SB2: NE
LegendThis sequence has been compared to family alignement (MSA) red => minority aminoacid blue => majority aminoacid color intensity => conservation rate title => sequence position(MSA position)aminoacid rate Catalytic site Catalytic site in the MSA MCMHFIELNSTTLHFSKTNSESAAPALVLINSLGTDFRIWDEFLVHLGHQ GEVLTYDKRGHGLSSVGDERYSIDLHMRDLAALMDSQSIKNAVICGVSVG GMIAMALQAARPDLVSGLILCDTAPRIGDAQTWQERINAIEANGMEGIAD TVMSRWFSSGFQAKWPEAVAGYRNLLCRTPLDGYTGTCAAIRDADLTCQA AQIDVPVLCVAGEDDQSTPPELVEEMACLIPNAKYERVGNCGHLPSLEQP EYLAHLVRQ
Reference
Title: Oxygen-controlled bacterial growth in the sponge Suberites domuncula: toward a molecular understanding of the symbiotic relationships between sponge and bacteria Muller WE, Grebenjuk VA, Thakur NL, Thakur AN, Batel R, Krasko A, Muller IM, Breter HJ Ref: Applied Environmental Microbiology, 70:2332, 2004 : PubMed
Sponges (phylum Porifera), known to be the richest producers among the metazoans of bioactive secondary metabolites, are assumed to live in a symbiotic relationship with microorganisms, especially bacteria. Until now, the molecular basis of the mutual symbiosis, the exchange of metabolites for the benefit of the other partner, has not been understood. We show with the demosponge Suberites domuncula as a model that the sponge expresses under optimal aeration conditions the enzyme tyrosinase, which synthesizes diphenols from monophenolic compounds. The cDNA isolated was used as a probe to determine the steady-state level of gene expression. The gene expression level parallels the level of specific activity in sponge tissue, indicating that without aeration the tyrosinase level drops drastically; this effect is reversible. The SB2 bacterium isolated from the sponge surface grew well in M9 minimal salt medium supplemented with the dihydroxylated aromatic compound protocatechuate; this carbon source supported growth more than did glucose. From the SB2 bacterium the protocatechuate gene cluster was cloned and sequenced. This cluster comprises all genes coding for enzymes involved in the conversion of protocatechuate to acetyl coenzyme A. Expression is strongly induced if the bacteria are cultivated on M9-protocatechuate medium; the genes pcaQ (encoding the putative transcriptional activator of the pca operon) and pcaDC were used for quantitative PCR analyses. We conclude that metabolites, in this case diphenols, which might be produced by the sponge S. domuncula are utilized by the sponge surface-associated bacterium for energy generation. This rationale will help to further uncover the symbiotic pathways between sponges and their associated "nonculturable" microorganisms; our approach is flanked by the establishment of an EST (expressed sequence tags) database in our laboratory.
