(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 > symbiont bacterium of Paederus fuscipes: 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 PWFCIHAAAGNVLCYRELAECLGIERPFYALQAPDAVGGGHPGSIVGLAA LYVRAIRIFQPWGPYFLAGWSMGGVVAYEMAQQLLQAGEQVEVLALLESY TPEAIRSLERKALGLSAESDDRMDKLLRTFAVELGIGETPWELSAVDLAQ GLEWILKRLEGSNLSTASFDLEQLHKLFRLYEANLNALDRYRLQPYSGRV VLIYADQTQQIDADEAQHLGGWQPWLRSGHCRSATIVGDHYSILQRPQVV QLAKVLTALVKDDGLATKYREVMVYS
References
Title: Evidence for a symbiosis island involved in horizontal acquisition of pederin biosynthetic capabilities by the bacterial symbiont of Paederus fuscipes beetles Piel J, Hofer I, Hui D Ref: Journal of Bacteriology, 186:1280, 2004 : PubMed
Pederin belongs to a group of antitumor compounds found in terrestrial beetles and marine sponges. It is used by apparently all members of the rove beetle genera Paederus and Paederidus as a chemical defense against predators. However, a recent analysis of the putative pederin biosynthesis (ped) gene cluster strongly suggests that pederin is produced by bacterial symbionts. We have sequenced an extended region of the symbiont genome to gain further insight into the biology of this as-yet-unculturable bacterium and the evolution of pederin symbiosis. Our data indicate that the symbiont is a very close relative of Pseudomonas aeruginosa that has acquired several foreign genetic elements by horizontal gene transfer. Besides one functional tellurite resistance operon, the region contains a genomic island spanning 71.6 kb that harbors the putative pederin biosynthetic genes. Several decayed insertion sequence elements and the mosaic-like appearance of the island suggest that the acquisition of the ped symbiosis genes was followed by further insertions and rearrangements. A horizontal transfer of genes for the biosynthesis of protective substances could explain the widespread occurrence of pederin-type compounds in unrelated animals from diverse habitats.
Title: A polyketide synthase-peptide synthetase gene cluster from an uncultured bacterial symbiont of Paederus beetles Piel J Ref: Proc Natl Acad Sci U S A, 99:14002, 2002 : PubMed
Many drug candidates from marine and terrestrial invertebrates are suspected metabolites of uncultured bacterial symbionts. The antitumor polyketides of the pederin family, isolated from beetles and sponges, are an example. Drug development from such sources is commonly hampered by low yields and the difficulty of sustaining invertebrate cultures. To obtain insight into the true producer and find alternative supplies of these rare drug candidates, the putative pederin biosynthesis genes were cloned from total DNA of Paederus fuscipes beetles, which use this compound for chemical defense. Sequence analysis of the gene cluster and adjacent regions revealed the presence of ORFs with typical bacterial architecture and homologies. The ped cluster, which is present only in beetle specimens with high pederin content, is located on a 54-kb region bordered by transposase pseudogenes and encodes a mixed modular polyketide synthase/nonribosomal peptide synthetase. Notably, none of the modules contains regions with homology to acyltransferase domains, but two copies of isolated monodomain acyltransferase genes were found at the upstream end of the cluster. In line with an involvement in pederin biosynthesis, the upstream cluster region perfectly mirrors pederin structure. The unexpected presence of additional polyketide synthase/nonribosomal peptide synthetase modules reveals surprising insights into the evolutionary relationship between pederin-type pathways in beetles and sponges.
