期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1992
卷号：89
期号：6
页码：2032-2035
DOI：10.1073/pnas.89.6.2032
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The gag genes of retroviruses encode nucleocapsid proteins that package genomic RNA and are essential for viral infectivity. These RNA binding proteins have a Cys-Xaa2-Cys-Xaa4-His-Xaa4-Cys zinc binding motif that is distinct from the typical zinc-finger motif Cys-Xaa2-Cys-Xaa12-14-His-Xaa2-His that is found in some transcriptional activators. Escherichia coli alanyl-tRNA synthetase contains a zinc-binding Cys-Xaa2-Cys-Xaa6-His-Xaa2-His motif that resembles that of retroviral nucleic acid binding proteins. We show here that, for alanyl-tRNA synthetase, the metal bound at the retroviral-like metal binding motif is important specifically for tRNA recognition and not for amino acid activation. Moreover, the enzyme-tRNA interaction is strongly dependent on the geometry of metal coordination to the protein. These and additional experiments collectively suggest a role for the retroviral-like metal binding motif in RNA recognition and, further, raise the possibility that the protein-bound metal itself participates in an RNA interaction.
