Solution structure of a SRP19 binding domain in human SRP RNA.
Assembly of the human signal recognition particle (SRP) requires SRP19 protein to bind to helices 6 and 8 of SRP RNA. In the present study, structure of a 29-mer RNA composing the SRP19 binding site in helix 6 was determined by NMR spectroscopy. The two A:C mismatches were continuously stacked to each other and formed wobble type A:C base pairs. The GGAG tetraloop in helix 6 was found to adopt a similar conformation to that of GNRA tetraloop, suggesting that these tetraloops are included in an extensive new motif GNRR. Compared with the crystal structure of helix 6 in complex with SRP19 determined previously, the GGAG tetraloop in the complex was found to adopt a similar conformation to the free form, although the loop structure becomes more open upon SRP19 binding. Thus, SRP19 is thought to recognize the overall fold of the GGAG loop.
Sakamoto
Taiichi
T
Department of Industrial Chemistry, Faculty of Engineering, Chiba Institute of Technology, Narashino, Chiba 275-0016, Japan.
Morita
Satoshi
S
Tabata
Kazutoshi
K
Nakamura
Kouji
K
Kawai
Gota
G
D001665:Binding Sites; D006801:Humans; D008958:Models, Molecular; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D020733:RNA, Small Cytoplasmic / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D018271:Signal Recognition Particle / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
C115990:7SL RNA; D020733:RNA, Small Cytoplasmic; C117074:SRP19 protein, human; D018271:Signal Recognition Particle