Specific binding of arginine to TAR RNA.
A single arginine residue within the basic region of the human immunodeficiency virus Tat protein mediates specific binding of Tat peptides to a three-nucleotide bulge in TAR RNA. It has been proposed that arginine recognizes TAR by forming a network of hydrogen bonds with two structurally distinct phosphates, an interaction termed the "arginine fork." Here it is shown that L-arginine blocks the Tat peptide/TAR interaction, whereas L-lysine and analogs of arginine that remove specific hydrogen bond donors do not. Experiments using an L-arginine affinity column demonstrate that arginine and the Tat peptides bind to the same site in TAR. Modification of two phosphates located at the junction of the double-stranded stem and bulge and modification of two adenine N7 groups in base-paired regions of TAR interfere with specific arginine binding. The results emphasize the importance of RNA structure in RNA-protein recognition and provide methods to identify arginine-binding sites in RNAs.
Tao
J
J
Whitehead Institute for Biomedical Research, Cambridge, MA 02142.
Frankel
A D
AD
D000225:Adenine / Q000737:chemistry; D000478:Alkylation; D001120:Arginine / Q000378:metabolism*; D001483:Base Sequence; D001667:Binding, Competitive; D015696:Gene Products, tat / Q000378:metabolism*; D015497:HIV-1 / Q000378:metabolism*; D008969:Molecular Sequence Data; D015394:Molecular Structure; D011485:Protein Binding; D012367:RNA, Viral / Q000378:metabolism* / Q000648:ultrastructure; D012045:Regulatory Sequences, Nucleic Acid; D012261:Ribonucleoproteins / Q000737:chemistry; D054322:tat Gene Products, Human Immunodeficiency Virus
D015696:Gene Products, tat; D012367:RNA, Viral; D012261:Ribonucleoproteins; D054322:tat Gene Products, Human Immunodeficiency Virus; D001120:Arginine; D000225:Adenine