Archaeal ribosomal protein L7 is a functional homolog of the eukaryotic 15.5kD/Snu13p snoRNP core protein
Archaeal ribosomal protein L7 is a functional homolog of the eukaryotic 15.5kD/Snu13p snoRNP core protein
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DOI：
10.1093/nar/30.4.931
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发表时间：
2002-02-15
影响因子：
14.9
通讯作者：
Maxwell, ES
中科院分区：
文献类型：
--
作者：
Kuhn, JF;Tran, EJ;Maxwell, ES
最近的研究已经在古细菌中发现了真核盒C/D小核核rna （snoRNAs）的同源物，称为sRNAs。box C/D snoRNP核心蛋白fibrarin和Nop56/58的古细菌同源物也已被鉴定，但真核生物15.5kD snoRNP蛋白的同源物尚未被描述。我们对古细菌基因组的序列分析表明，高度保守的核糖体蛋白L7与真核生物的15.5kD蛋白具有广泛的同源性。蛋白结合研究表明，重组jannaschii methanoccoccus L7蛋白结合box C/D snoRNA核心基序具有与真核生物15.5kD蛋白相同的特异性和亲和力。与真核生物15.5kD核心蛋白相同，古细菌L7需要正确折叠的box C/D核心基序和完整的box C和D核心基序。突变分析表明，L7相互作用也需要15.5kD结合所必需的box C/D核心基序的关键特征。这些包括并置框C和D的茎I，以及剪切的G:A对和不对称凸起区域突出的嘧啶核苷酸。L7Ae在Haloarcula marismortui 50S核糖体亚基中的存在，以及我们对L7结合盒C/D snoRNA核心基的能力的证明，表明该蛋白在古细菌中起双重作用。L7作为sRNP核心蛋白和核糖体蛋白，可能调节和协调sRNP组装与核糖体的生物发生。
Recent investigations have identified homologs of eukaryotic box C/D small nucleolar RNAs (snoRNAs) in Archaea termed sRNAs. Archaeal homologs of the box C/D snoRNP core proteins fibrillarin and Nop56/58 have also been identified but a homolog for the eukaryotic 15.5kD snoRNP protein has not been described. Our sequence analysis of archaeal genomes reveals that the highly conserved ribosomal protein L7 exhibits extensive homology with the eukaryotic 15.5kD protein. Protein binding studies demonstrate that recombinant Methanoccocus jannaschii L7 protein binds the box C/D snoRNA core motif with the same specificity and affinity as the eukaryotic 15.5kD protein. Identical to the eukaryotic 15.5kD core protein, archaeal L7 requires a correctly folded box C/D core motif and intact boxes C and D. Mutational analysis demonstrates that critical features of the box C/D core motif essential for 15.5kD binding are also required for L7 interaction. These include stem I which juxtaposes boxes C and D, as well as the sheared G:A pairs and protruded pyrimidine nucleotide of the asymmetric bulge region. The demonstrated presence of L7Ae in the Haloarcula marismortui 50S ribosomal subunit, taken with our demonstration of the ability of L7 to bind to the box C/D snoRNA core motif, indicates that this protein serves a dual role in Archaea. L7 functioning as both an sRNP core protein and a ribosomal protein could potentially regulate and coordinate sRNP assembly with ribosome biogenesis.