کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6288205 1615929 2008 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Rhamnose catabolism in Bacteroides thetaiotaomicron is controlled by the positive transcriptional regulator RhaR
موضوعات مرتبط
علوم زیستی و بیوفناوری ایمنی شناسی و میکروب شناسی میکروبیولوژی و بیوتکنولوژی کاربردی
پیش نمایش صفحه اول مقاله
Rhamnose catabolism in Bacteroides thetaiotaomicron is controlled by the positive transcriptional regulator RhaR
چکیده انگلیسی
Bacteroides thetaiotaomicron is an important human gut commensal, which also causes opportunistic infections outside this environment. It utilises a range of host and diet-related carbohydrates, including rhamnose. In this study, the rha gene cluster, required for rhamnose utilisation, was characterised by transcription analysis, gene targeted mutagenesis and enzyme assays. Growth in the presence of l-rhamnose induced transcription of all the genes of this cluster. The first five genes of the cluster, rhaKIPAO, were transcribed as an operon from a transcriptional start site upstream of rhaK, whereas the sixth gene, rhaR, was transcribed independently. Bioinformatic analysis and mutation of the rhaR gene identified it as encoding the positive transcriptional activator of rhaKIPAO. A rhaR mutant could not utilise rhamnose as the sole carbon source but grew normally on glucose. The rhaO gene encoded a lactaldehyde reductase, and a rhaO mutant produced reduced levels of l-1,2-propanediol during growth in rhamnose, indicating its contribution to rhamnose catabolism in Bacteroides thetaiotaomicron.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Research in Microbiology - Volume 159, Issues 9–10, November–December 2008, Pages 678-684
نویسندگان
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