對(duì)從由海水樣品提取出的物質(zhì)獲得的環(huán)境DNA 和RNA序列所做的計(jì)算分析,，顯示了豐富的細(xì)菌非編碼RNA（ncRNA）的存在,，它們?cè)诖笮『蛷?fù)雜性上很像大型核糖酶。人們特別感興趣的是兩種新發(fā)現(xiàn)的RNA,，被稱為GOLLD 和 HEARO,，它們是迄今所發(fā)現(xiàn)的最大、最復(fù)雜的RNA之一,。這些發(fā)現(xiàn)表明,，在水中、土壤中和尚未探索的其他環(huán)境中,，存在很多有待發(fā)現(xiàn)的具有超大尺寸,、復(fù)雜結(jié)構(gòu)或其他特別之處的RNA。（生物谷Bioon.com）
生物谷推薦原始出處：
Nature 462, 656-659 (3 December 2009) | doi:10.1038/nature08586
Exceptional structured noncoding RNAs revealed by bacterial metagenome analysis
Zasha Weinberg1,2, Jonathan Perreault2, Michelle M. Meyer2 & Ronald R. Breaker1,2,3
1 Howard Hughes Medical Institute,
2 Department of Molecular, Cellular and Developmental Biology,
3 Department of Molecular Biophysics and Biochemistry, Yale University, Box 208103, New Haven, Connecticut 06520-8103, USA
Correspondence to: Ronald R. Breaker1,2,3 Correspondence and requests for materials should be addressed to R.R.B.
Estimates of the total number of bacterial species1, 2, 3 indicate that existing DNA sequence databases carry only a tiny fraction of the total amount of DNA sequence space represented by this division of life. Indeed, environmental DNA samples have been shown to encode many previously unknown classes of proteins4 and RNAs5. Bioinformatics searches6, 7, 8, 9, 10 of genomic DNA from bacteria commonly identify new noncoding RNAs (ncRNAs)10, 11, 12 such as riboswitches13, 14. In rare instances, RNAs that exhibit more extensive sequence and structural conservation across a wide range of bacteria are encountered15, 16. Given that large structured RNAs are known to carry out complex biochemical functions such as protein synthesis and RNA processing reactions, identifying more RNAs of great size and intricate structure is likely to reveal additional biochemical functions that can be achieved by RNA. We applied an updated computational pipeline17 to discover ncRNAs that rival the known large ribozymes in size and structural complexity or that are among the most abundant RNAs in bacteria that encode them. These RNAs would have been difficult or impossible to detect without examining environmental DNA sequences, indicating that numerous RNAs with extraordinary size, structural complexity, or other exceptional characteristics remain to be discovered in unexplored sequence space.
