Guogas Laura M, Filman David J, Hogle James M, Gehrke Lee
Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115, USA.
Science. 2004 Dec 17;306(5704):2108-11. doi: 10.1126/science.1103399.
Alfalfa mosaic virus genomic RNAs are infectious only when the viral coat protein binds to the RNA 3' termini. The crystal structure of an alfalfa mosaic virus RNA-peptide complex reveals that conserved AUGC repeats and Pro-Thr-x-Arg-Ser-x-x-Tyr coat protein amino acids cofold upon interacting. Alternating AUGC residues have opposite orientation, and they base pair in different adjacent duplexes. Localized RNA backbone reversals stabilized by arginine-guanine interactions place the adenosines and guanines in reverse order in the duplex. The results suggest that a uniform, organized 3' conformation, similar to that found on viral RNAs with transfer RNA-like ends, may be essential for replication.
苜蓿花叶病毒基因组RNA只有在病毒外壳蛋白与RNA 3'末端结合时才具有感染性。苜蓿花叶病毒RNA-肽复合物的晶体结构表明,保守的AUGC重复序列和脯氨酸-苏氨酸-x-精氨酸-丝氨酸-x-x-酪氨酸外壳蛋白氨基酸在相互作用时会共同折叠。交替的AUGC残基具有相反的方向,它们在不同的相邻双链体中形成碱基对。由精氨酸-鸟嘌呤相互作用稳定的局部RNA主链反转使双链体中的腺苷和鸟嘌呤顺序颠倒。结果表明,一种与具有类似转运RNA末端的病毒RNA上发现的3'构象相似的均匀、有组织的3'构象可能对复制至关重要。