Barlass, P.J., Houston, C.W., Clements, M.O. and Moir, A. 2002. Germination of Bacillus cereus spores in response to L-alanine and to inosine: the roles of gerL and gerQ operons. Microbiology. 148 (7), pp. 2089-2095.
| Title | Germination of Bacillus cereus spores in response to L-alanine and to inosine: the roles of gerL and gerQ operons |
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| Authors | Barlass, P.J., Houston, C.W., Clements, M.O. and Moir, A. |
| Abstract | Bacillus cereus 569 (ATCC 10876) endospores germinate in response to inosine or L-alanine, the most rapid germination response being elicited by a combination of these germinants. The gerI operon has already been characterized as a homologue of the gerA spore-germination receptor family of operons found in all Bacillus spp. examined; the primary defect in gerI mutant spores is in the inosine germination response, although spores were also slower to germinate in L-alanine. Additional transposon-insertion mutants, from similar Tn917-LTV1 mutagenesis and enrichment experiments, now define two more operons, also members of the family of gerA homologues, important in L-alanine and inosine germination. Transposon insertions were identified in an alanine-specific germination locus, named gerL, which represents an operon of three genes, termed gerLA, gerLB and gerLC. By examining the residual germination response to L-alanine in gerI and gerL mutants, it was deduced that the GerL proteins contribute most strongly to the L-alanine germination response, and that the GerI proteins, required primarily in inosine germination, mediate only much slower germination responses to alanine. The L-alanine germination responses mediated by GerL and GerI proteins differ in their germination rates, temperature optima and germinant concentration dependence. The gerQ locus, again identified by transposon insertion, is a second inosine-related germinant-receptor operon. GerQ and GerI proteins are both required for the germination response to inosine as sole germinant, but GerQ has no role in L-alanine germination. Although near-identical homologues of gerI and gerL operons are evident in the Bacillus anthracis genome sequence, there is no evidence of a close homologue of gerQ. |
| Keywords | Bacillus anthracis, gerA, germinant, receptor, endospore |
| Journal | Microbiology |
| Journal citation | 148 (7), pp. 2089-2095 |
| ISSN | 1350-0872 |
| Year | Jul 2002 |
| Web address (URL) | http://mic.sgmjournals.org/cgi/content/full/148/7/2089 |
| Publication dates | |
| Published | Jul 2002 |
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