Galizzi A, Albertini A M, Plevani P, Cassani G
Mol Gen Genet. 1976 Oct 18;148(2):159-64. doi: 10.1007/BF00268380.
Bacillus subtilis strain PB 2427 temperature sensitive in the synthesis of RNA during spore germination and outgrowth has been characterized to some extent. At non permissive temperature (46 degrees C) strain PB 2427 synthesizes stable and unstable RNA for 50 min from the beginning of germination and then stops. Most of the stable RNA is degraded to shorter molecules but can be identified as ribosomal RNA by hybridization-competition experiments. At non permissive temperature, in the presence of chloramphenicol, synthesis of RNA proceeds, though at a reduced rate, for at least 90 min. By hybridization-competition experiments it can also be shown that the RNA synthesized at 46 degrees C in the presence of chloramphenicol includes transcripts that are absent, from the RNA synthesized at 46 degrees C in the absence of drug. The RNA polymerase (holo and core) purified from vegatative cells of the mutant strain does not appear to have a greater heat-lability as compared with the enzyme purified from the parental strain. At non permissive temperature only six polypeptide chains with MW ranging from 47,000 to 78,000 daltons are synthesized by the germinating spores of the mutant.
枯草芽孢杆菌PB 2427菌株在孢子萌发和生长过程中RNA合成对温度敏感,已在一定程度上得到了表征。在非允许温度(46℃)下,PB 2427菌株从萌发开始合成稳定和不稳定RNA达50分钟,然后停止。大部分稳定RNA被降解为较短的分子,但通过杂交竞争实验可鉴定为核糖体RNA。在非允许温度下,在氯霉素存在的情况下,RNA合成至少持续90分钟,尽管速率有所降低。通过杂交竞争实验还可以表明,在46℃氯霉素存在下合成的RNA包括在46℃无药物时合成的RNA中不存在的转录本。与从亲本菌株纯化的酶相比,从突变菌株营养细胞中纯化的RNA聚合酶(全酶和核心酶)似乎没有更大的热不稳定性。在非允许温度下,突变体萌发的孢子仅合成六条分子量在47,000至78,000道尔顿之间的多肽链。