Kyoto University · Environmental Science
Professor Hiroyuki Ogata's research lab specializes in computational biology and bioinformatics, focusing on genome analysis, functional annotation, and systems biology of microbial genomes—particularly intracellular bacteria such as Rickettsia. The lab develops advanced computational methods for comparative genomics, pathway analysis, and protein function prediction, with a strong emphasis on leveraging databases like KEGG to decode biological networks and evolutionary mechanisms. Key research directions include identifying gene transfer systems in obligate intracellular pathogens, analyzing genome evolution through comparative genomics, and creating high-performance tools for functional annotation of genes and proteins.
Figures are computed from collected data and may differ slightly.
Supplementary data are available at Bioinformatics online.
Rickettsia conorii is an obligate intracellular bacterium that causes Mediterranean spotted fever in humans. We determined the 1,268,755-nucleotide complete genome sequence of R. conorii, containing 1374 open reading frames. This genome exhibits 804 of the 834 genes of the previously determined R. prowazekii genome plus 552 supplementary open reading frames and a 10-fold increase in the number of repetitive elements. Despite these differences, the two genomes exhibit a nearly perfect colinearity
The recently sequenced Rickettsia felis genome revealed an unexpected plasmid carrying several genes usually associated with DNA transfer, suggesting that ancestral rickettsiae might have been endowed with a conjugation apparatus. Here we present the genome sequence of Rickettsia bellii, the earliest diverging species of known rickettsiae. The 1,552,076 base pair-long chromosome does not exhibit the colinearity observed between other rickettsia genomes, and encodes a complete set of putative con
We sequenced the genome of Rickettsia felis, a flea-associated obligate intracellular alpha-proteobacterium causing spotted fever in humans. Besides a circular chromosome of 1,485,148 bp, R. felis exhibits the first putative conjugative plasmid identified among obligate intracellular bacteria. This plasmid is found in a short (39,263 bp) and a long (62,829 bp) form. R. felis contrasts with previously sequenced Rickettsia in terms of many other features, including a number of transposases, severa
The availability of computerized knowledge on biochemical pathways in the KEGG database opens new opportunities for developing computational methods to characterize and understand higher level functions of complete genomes. Our approach is based on the concept of graphs; for example, the genome is a graph with genes as nodes and the pathway is another graph with gene products as nodes. We have developed a simple method for graph comparison to identify local similarities, termed correlated cluste
Abstract Summary KofamKOALA is a web server to assign KEGG Orthologs (KOs) to protein sequences by homology search against a database of profile hidden Markov models (KOfam) with pre-computed adaptive score thresholds. KofamKOALA is faster than existing KO assignment tools with its accuracy being comparable to the best performing tools. Function annotation by KofamKOALA helps linking genes to KEGG resources such as the KEGG pathway maps and facilitates molecular network reconstruction. Availabil
Metagrowth is a new type of knowledge base developed to guide the experimental studies of culture conditions of obligate parasitic bacteria. We have gathered biological evidences giving possible clues to the development of the axenic (i.e. 'cell-free') growth of obligate parasites from various sources including published literature, genomic sequence information, metabolic databases and transporter databases. The database entries are composed of those evidences and specific hypotheses derived fro
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