1990 Fiscal Year Final Research Report Summary
Study of the Recognition of Germinants in Bacillus Megaterium Spore
| Project/Area Number |
01570234
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
細菌学
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| Research Institution | Osaka University |
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Principal Investigator |
KONDO Masaomi Osaka Univ., Pharmaceutical Sci., Professor, 薬学部, 教授 (90028829)
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| Co-Investigator(Kenkyū-buntansha) |
TANI Katsuji Osaka Univ., Pharmaceutical Sci., Research Associate, 薬学部, 助手 (50217113)
TAKUBO Yoshihiro Osaka Univ., Pharmaceutical Sci., Assistant Professor, 薬学部, 助教授 (40171590)
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| Project Period (FY) |
1989 – 1990
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| Keywords | B. megaterium / Germination mutant / Transposon mutagenesis / Germination gene / Cloning / Sequence / Cortex |
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| Research Abstract |
The DNA sequence of the gene encoding the protein, which may be responsible for the recognition of the germinants, e. g. glucose, proline and leucine in Bacillus megaterium ATCC 12872, was determined and the result can be summarized as follows. 1) there is one ORP encoding 30 kDa protein, 2) the encoded protein seems to be very hydrophilic from its amino acid composition, and 3) its promoter has the same consensus sequence as that recognized by sigma^<43> subunit of RNA holoenzyme. But, this gene was found to possess no sequence homology to any genes already known.
Moreover, we isolated two different types of germination mutants of B. Megaterium ATCC 12872, that is, type A which does not germinate by all germinants tested (TM-4) and type B which easily germinates only by de-ionized water (TM-23) using transposon Tn917. The volume ratio of cortex / (cortex + protoplast) of the spore of TM-23 increased and became to be germinated by deionized water after treatment with sodium dodecylsulfatedithiotreitol (pH 9.8). Osmoregulatory expansion may be insufficient in this strain.
On the other hand, not only dipicolinic acid but also heat-resistance were not lost when the spore of TM-4 were incubated with germinants, which suggests a gene associated with an initial and common pathway of germination is mutagenized in this strain. The DNA sequence of a Tn917-inserted gene was determined, but no sequence homology was found to any genes already known.
Two germination genes in B. Subtilisin, gerA and gerB encodes a membrane-bound protein and a DNA-binding protein, respectively, but it has become apparent that both germination genes in B. Megatherium encoded new proteins. The function of these proteins in germinatio remains to be investigated.
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