Keigoh Ohnishi

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BACKGROUND The pluripotent state of embryonic stem (ES) cells is controlled by a network of specific transcription factors. Recent studies also suggested the significant contribution of mitochondria on the regulation of pluripotent stem cells. However, the molecules involved in these regulations are still unknown. METHODOLOGY/PRINCIPAL FINDINGS In this(More)
Published sequence data of MHC genes, cDNAs and MHC products were analyzed for their sequence homologies. Alignment statistics revealed that class I gene products consist of four mutually homologous domains, and that class II beta gene products is composed of three mutually homologous domains. Not only extracellular domains but also newly discovered(More)
tRNA was found to have emerged by tandem duplication of a ca. 37-base RNA ("semi-tRNA"). The most ancestral anticodon was "(5')CCA(3')". The peptidyltransferase (PT) region of 23S rRNA was concluded to be a 5S rRNA homologue. Important evidences were obtained for elucidating that the RNA transcript from the Bacillus subtilis (BSU) trrnD operon is a relic of(More)
The bases 1175-1542 (3'-term.) and 94-510 of the E. coli (EC) 16S rRNA are both homologous to the [5S rRNA-tRNA Asn-tRNA(Ser)-tRNA(Glu)-tRNA(Val)-tRNA(Met)] region of the Bacillus subtilis (BSU) trrnD operon, and to the S12 and S7 r-protein-encoding region (S12/S7 region) in the EC str operon. The 2570-2906 (3'-term.) of the EC 23S rRNA is also homologous(More)
Internal homology units of F1-ATPase epsilon and gamma subunits were searched by computer-aided methods. The epsilon in E. coli (EC) and maize chloroplast (Ch1) was found to consist of three homologous domains, named domains I, II and III (amino acids 1-47, 48-95 and 96-139 for EC). The gamma in E. coli was demonstrated to have at least six homologous(More)
Two intragenomic homologous sequence pairs were detected in poliovirion type 1 (Mahoney) RNA. An RNA sequence region N3729-N4118 (by the numbering of Kitamura et al. (ref. 1)) coding for P2-3b was found to share 39% identical bases in 360 aligned positions with another region N5007-N5366 encoding P2-X and P3-1b. An RNA segment N3381-N3558 coding for the(More)
The lambda phage cI gene and E. coli rpoD gene encoding the lambda repressor and sigma factor, respectively, were aligned with each other based on the internal homologies found in the rpoD gene. Statistical evaluations for these intragenic and intergenic base sequence homologies in the corresponding alignments have conclusively demonstrated that the rpoD(More)
The 330 residue-long N-terminal domains (NTDs) of beta and beta' subunits of the Escherichia coli RNA polymerase (RPase) core enzyme were found to be significantly homologous to the entire length of its alpha subunit. The C-terminal domains (CTDs) of the RPase beta subunit and DNA primase (dnaG protein) were not only strongly homologous to each other but(More)