Fitz-Gibbon Sorel T, Ladner Heidi, Kim Ung-Jin, Stetter Karl O, Simon Melvin I, Miller Jeffrey H
Department of Microbiology, Immunology, and Molecular Genetics, and Molecular Biology Institute, University of California, Los Angeles, CA 90095-1489, USA.
Proc Natl Acad Sci U S A. 2002 Jan 22;99(2):984-9. doi: 10.1073/pnas.241636498. Epub 2002 Jan 15.
We determined and annotated the complete 2.2-megabase genome sequence of Pyrobaculum aerophilum, a facultatively aerobic nitrate-reducing hyperthermophilic (T(opt) = 100 degrees C) crenarchaeon. Clues were found suggesting explanations of the organism's surprising intolerance to sulfur, which may aid in the development of methods for genetic studies of the organism. Many interesting features worthy of further genetic studies were revealed. Whole genome computational analysis confirmed experiments showing that P. aerophilum (and perhaps all crenarchaea) lack 5' untranslated regions in their mRNAs and thus appear not to use a ribosome-binding site (Shine-Dalgarno)-based mechanism for translation initiation at the 5' end of transcripts. Inspection of the lengths and distribution of mononucleotide repeat-tracts revealed some interesting features. For instance, it was seen that mononucleotide repeat-tracts of Gs (or Cs) are highly unstable, a pattern expected for an organism deficient in mismatch repair. This result, together with an independent study on mutation rates, suggests a "mutator" phenotype.
我们测定并注释了嗜氧栖热菌（Pyrobaculum aerophilum）完整的220万个碱基对的基因组序列，嗜氧栖热菌是一种兼性好氧、能进行硝酸盐还原的超嗜热（最适生长温度T(opt)=100摄氏度）泉古菌。研究发现了一些线索，有助于解释该生物体对硫惊人的不耐受性，这可能有助于开发对该生物体进行基因研究的方法。还揭示了许多值得进一步进行基因研究的有趣特征。全基因组计算分析证实了实验结果，即嗜氧栖热菌（可能所有泉古菌）的mRNA缺乏5'非翻译区，因此似乎不使用基于核糖体结合位点（Shine-Dalgarno）的机制在转录本的5'端起始翻译。对单核苷酸重复序列的长度和分布进行检查后发现了一些有趣的特征。例如，发现G（或C）的单核苷酸重复序列高度不稳定，这是错配修复缺陷生物体预期的模式。这一结果，连同对突变率的独立研究，表明其具有“突变体”表型。
