کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9885551 | 1537329 | 2005 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Genes coding for SecG and Leu2-tRNA form an operon to give an unusual RNA comprising mRNA and a tRNA precursor
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موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The secG gene encoding the SecG subunit of the SecYEG translocon and the leuU gene encoding Leu2-tRNA are very closely located on the Escherichia coli chromosome. A secG-leuU disruptant was not viable unless secG-leuU was induced from a plasmid, indicating that leuU is an essential gene since secG is dispensable at 37 °C. A mutant strain in which the promoter region for secG was replaced with cat revealed the same phenotype as the secG-leuU disruptant, indicating that leuU was expressed from the secG promoter. When the secG-leuU locus was placed on a high copy plasmid, an RNA comprising both mRNA for SecG and a precursor for Leu2-tRNA was detected on a Northern blot. Moreover, a secG-leuU transcript was amplified by RT-PCR using the total RNA fraction prepared from wild type E. coli cells but not from the secG-leuU and the secG promoter disruptants, indicating that secG-leuU forms an operon. Thus, the expression of Leu2-tRNA requires expression of the upstream secG gene. The gene structure of secG-leuU was conserved among Gram-negative bacteria, although the sequences separating the two genes were quite diverse. The physiological significance of this unusual gene organization is discussed.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression - Volume 1729, Issue 3, 10 July 2005, Pages 166-173
Journal: Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression - Volume 1729, Issue 3, 10 July 2005, Pages 166-173
نویسندگان
Ken-ichi Nishiyama, Hajime Tokuda,