tailieunhanh - Báo cáo sinh học: "SnoPatrol: how many snoRNA genes are there"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: SnoPatrol: how many snoRNA genes are there? | Gardner et al. Journal of Biology 2010 9 4 http content 9 1 4 Journal of Biology MINIREVIEW L__ SnoPatrol how many snoRNA genes are there Paul P Gardner 1 Alex Bateman1 and Anthony M Poole2-3 See research articles http 1471-2164 10 515 and http 1471-2164 11 61 Abstract Small nucleolar RNAs snoRNAs are among the most evolutionarily ancient classes of small RNA. Two experimental screens published in BMC Genomics expand the eukaryotic snoRNA catalog but many more snoRNAs remain to be found. What are snoRNAs The biosynthesis of eukaryote ribosomes is complex involving numerous processing events to generate mature ribosomal RNAs rRNAs and the subsequent assembly of processed rRNAs with dozens of ribosomal proteins. Small nucleolar RNAs snoRNAs are central to ribosome maturation being required in key cleavage steps to generate individual rRNAs and in their capacity as guides for site-specific modification of rRNA. In the rRNA of the budding yeast Saccharomyces cerevisiae on the order of 100 snoRNA-guided modifications are made during the biosynthesis of a single ribosome this number is approximately double in humans. Around half of these modifications are methylations of the 2 position on ribose and are carried out by C D-box small nucleolar ribonucleoproteins snoRNPs which consist of a guide snoRNA acting in concert with several proteins including Nop1p the RNA methylase component of the snoRNP. The remaining modifications produce pseudouridine an isomer of uridine and are guided by H ACA-box snoRNPs with the Cbf5p subunit performing the pseudouridylation reaction 1 . Figure 1 illustrates the interaction between the two types of snoRNA and their respective RNA targets. Over the past decade the snoRNA universe has expanded rapidly. H ACA- and C D-family RNAs have been discovered in Archaea where they are dubbed sRNAs as Archaea lack nucleoli and likewise modify Correspondence pg5@ Wellcome Trust .