Analysis of and function predictions for previously conserved hypothetical or putative proteins in Blochmannia floridanus

BACKGROUND: There is an increasing interest to better understand endosymbiont capabilities in insects both from an ecological point of view and for pest control. Blochmannia floridanus provides important nutrients for its host, the ant Camponotus, while the bacterium in return is provided with a niche to proliferate. Blochmannia floridanus proteins and metabolites are difficult to study due to its endosymbiontic life style; however, its complete genome sequence became recently available. RESULTS: Improved sequence analysis algorithms, databanks and gene and pathway context methods allowed us to reveal new information on various enzyme and pathways from the Blochmannia floridanus genome sequence [EMBL-ID BX248583]. Furthermore, these predictions are supported and linked to experimental data for instance from structural genomics projects (e.g. Bfl341, Bfl 499) or available biochemical data on proteins from other species which we show here to be related. We were able to assign a confirmed or at least a putative molecular function for 21 from 27 previously conserved hypothetical proteins. For 48 proteins of 66 with a previous putative assignment the function was further clarified. Several of these proteins occur in many proteobacteria and are found to be conserved even in the compact genome of this endosymbiont. To extend and re-test predictions and links to experimentally verified protein functions, functional clusters and interactions were assembled. These included septum initiation and cell division (Bfl165, Bfl303, Bfl248 et al.); translation; transport; the ubiquinone (Bfl547 et al.), the inositol and nitrogen pathways. CONCLUSION: Taken together, our data allow a better and more complete description of the pathway capabilities and life style of this typical endosymbiont

Metabolic Interdependence of Obligate Intracellular Bacteria and Their Insect Hosts

Mutualistic associations of obligate intracellular bacteria and insects have attracted much interest in the past few years due to the evolutionary consequences for their genome structure. However, much less attention has been paid to the metabolic ramifications for these endosymbiotic microorganisms, which have to compete with but also to adapt to another metabolism—that of the host cell. This review attempts to provide insights into the complex physiological interactions and the evolution of metabolic pathways of several mutualistic bacteria of aphids, ants, and tsetse flies and their insect hosts

Replication of the Endosymbiotic Bacterium Blochmannia floridanus Is Correlated with the Developmental and Reproductive Stages of Its Ant Host

The dynamics of replication of the intracellular endosymbiotic bacterium Blochmannia floridanus was determined during the larval development of its host ant Camponotus floridanus by real-time quantitative PCR. The bacteria were found to proliferate during pupation and immediately after the eclosion of the imagines (adult ants). In older workers the number of bacteria present in the midgut bacteriocytes decreased significantly. In contrast, the bacterial population in the ovaries was dependent on the reproductive state of the animal. An age-dependent degeneration of the midgut bacteriocytes was also investigated by microscopic techniques in males and female castes of the closely related ant species C. herculeanus and C. sericeiventris, respectively, with similar results and supports the concept of age-dependent degeneration of the midgut bacteriocytes in all castes

Relevance of the Endosymbiosis of Blochmannia floridanus and Carpenter Ants at Different Stages of the Life Cycle of the Host

Expression of several genes possibly involved in the symbiotic relationship between the obligate intracellular endosymbiont Blochmannia floridanus and its ant host Camponotus floridanus was investigated at different developmental stages of the host by real-time quantitative PCR. These included a set of genes related to nitrogen metabolism (ureC, ureF, glnA, and speB) as well as genes involved in the synthesis of the aromatic amino acid tyrosine (tyrA, aspC, and hisC). The overall transcriptional activity of Blochmannia was found to be quite low during early developmental stages and to increase steadily with host age. However, a concerted peak of gene expression related to nitrogen recycling could be detected around the entire process of pupation, while expression of biosynthesis pathways for aromatic amino acids was elevated only during a short phase in pupation. These data suggest an important role of certain metabolic functions for the symbiotic interactions of the bacteria and an individual host organism in early phases of development. General relevance of Blochmannia for its ant host was tested in fostering experiments with worker groups of Camponotus floridanus, and their success in raising pupae from first-instar larvae was used as a fitness measure. Groups treated with antibiotics had a significantly reduced success in raising the brood in comparison to untreated control groups, indicating that the symbiosis is relevant for the development of the entire colony

Analysis of and function predictions for previously conserved hypothetical or putative proteins in -3

<p><b>Copyright information:</b></p><p>Taken from "Analysis of and function predictions for previously conserved hypothetical or putative proteins in "</p><p>BMC Microbiology 2006;6():1-1.</p><p>Published online 9 Jan 2006</p><p>PMCID:PMC1360075.</p><p>Copyright © 2006 Gaudermann et al; licensee BioMed Central Ltd.</p> the homology model (starting from residue 1, a Met in Bfl341). Important predicted catalytic residues outline the substrate cleft. These are His 130, Arg 180, Glu 217 and Arg 281 of Bfl341 corresponding to His 148, Arg 196, Glu 212, and Arg 274 in the template structure (four from five conserved residues known for the family and those checked from by mutagenesis to be important for catalysis in vitro [24]). Kajander et al. [24] did not know yet the accurate molecular function of the structure they solved. However, regarding the high sequence similarity of Bfl341 (38% identical, 57% similar residues) to recently characterized Pgl protein [25], the actual activity of Bfl341 we now predict to be a 6-phosphogluconolactonase

Analysis of and function predictions for previously conserved hypothetical or putative proteins in -0

<p><b>Copyright information:</b></p><p>Taken from "Analysis of and function predictions for previously conserved hypothetical or putative proteins in "</p><p>BMC Microbiology 2006;6():1-1.</p><p>Published online 9 Jan 2006</p><p>PMCID:PMC1360075.</p><p>Copyright © 2006 Gaudermann et al; licensee BioMed Central Ltd.</p>nclude: a MFS family transporter (Bfl240, IolF-like, top right; exact substrate specificity not known), ADP-heptose synthase (Bfl063, IolC-like), an acetolactate synthase II, large subunit (Bfl593; IolD-like) and its small subunit, neighbouring protein Bfl 592 (both proteins should physically interact), fructose 1,6-bisphosphate aldolase (Bfl255, IolJ-like; this enzyme is also involved in glycolysis) and predicted myo-inositol-1(or 4)-monophosphatase (Bfl535; related to the Archaeal fructose-1,6-bisphosphatase and related enzymes of inositol monophosphatase family). Bfl601 (triosephosphate isomerase) finishes the pathway converting created dihydroxyacetone phosphate into glyceraldehyde 3-phosphate