Eubacterial components similar to small nuclear ribonucleoproteins: identification of immunoprecipitable proteins and capped RNAs in a cyanobacterium and a gram-positive eubacterium.
Eubacterial components similar to small nuclear ribonucleoproteins: identification of immunoprecipitable proteins and capped RNAs in a cyanobacterium and a gram-positive eubacterium.
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与小核核糖核蛋白相似的真细菌成分：蓝藻和革兰氏阳性真细菌中免疫沉淀蛋白和加帽 RNA 的鉴定。
DOI：
10.1128/jb.175.7.1871-1878.1993
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发表时间：
1993
影响因子：
3.2
通讯作者：
Silva,V
中科院分区：
文献类型：
--
作者：
Kovacs,SA;O'Neil,J;Watcharapijarn,J;Moe-Kirvan,C;Vijay,S;Silva,V
Small nuclear ribonucleoprotein (snRNP) particles play an important role in the processing of pre-mRNA. snRNPs have been identified immunologically in a variety of cells, but none have ever been observed in prokaryotic systems. This report provides the first evidence for the presence of snRNP-like components in two types of prokaryotic cells: those of the cyanobacterium Synechococcus leopoliensis and those of the gram-positive eubacterium Bacillus subtilis. These components consist of snRNP-immunoreactive proteins and RNAs, including some with the snRNP-unique 5' m2,2,7G (m3G) cap. Immunoreactivity was determined by immunoprecipitation procedures, with either antinuclear-antibody-positive (RNP- and Sm-monospecific) patient sera or a m3G monoclonal antibody, with radiolabelled cell extracts that were preadsorbed with antinuclear-antibody-negative sera. S. leopoliensis immunoprecipitates showed the presence of high-molecular-mass proteins (14 to 70 kDa) and RNAs (138 to 243 nucleotides) that are analogous in size to proteins and RNAs found in human (HEp-2) cell immunoprecipitates but absent in Escherichia coli immunoprecipitates. Thin-layer chromatography of S. leopoliensis immunoprecipitates confirmed the presence of a capped nucleotide similar to a capped nucleotide in HEp-2 immunoprecipitates; no such nucleotide was observed in E. coli immunoprecipitates. Immunoreactive RNAs (117-170 nucleotides) were identified in a second eubacterium, B. subtilis, as well. This work suggests that snRNPs or their evolutionary predecessors predate the emergence of eukaryotic cells.
