TY - JOUR
T1 - Solution structure of protein SRP19 of Archaeoglobus fulgidus signal recognition particle
AU - Pakhomova, Olga N.
AU - Deep, Shashank
AU - Huang, Qiaojia
AU - Zwieb, Christian
AU - Hinck, Andrew P.
N1 - Funding Information:
We gratefully acknowledge Frank Delaglio for the NMR processing package nmrPipe, Dan Garrett for the NMR data analysis package PIPP, Ad Bax for the IPAP-HSQC pulse program and the RDC analysis package PALES, Nico Tjandra and Marius Clore for the X-PLOR routines that enabled refinement of the structures against the experimental residual dipolar coupling data, and Zhanyong Shu, who assisted in the measurement and analysis of the backbone relaxation parameters. This work was supported by NIH grants GM49034 to C.Z. and RR13879 to A.P.H. and Robert A. Welch Foundation grant AQ-1413 to A.P.H.
PY - 2002
Y1 - 2002
N2 - Protein SRP19 is an essential RNA-binding component of the signal recognition particle (SRP) in Archaea and Eucarya. A three-dimensional solution structure of the 104 residue SRP19 from the hyperthermophilic archaeon Archaeoglobus fulgidus, designated as Af19, was determined by NMR spectroscopy. Af19 contains three β-strands, two α-helical regions, arranged in a βαββα topology, a 310 helix, and a disordered C-terminal tail. This fold is similar to the βαββαβ RNP motif present in numerous other RNA-binding proteins, which engage their cognate RNAs using conserved sequence motifs present within β-strands 1 and 3. Mutagenesis studies of human SRP19, however, reveal the major contact sites with SRP RNA reside within loops 1, 3, and 4. These contacts were verified by the crystal structure of human SRP19 complexed to SRP RNA helix 6 reported subsequent to the submission of the manuscript. The crystal structure also reveals that, unlike canonical RNP motifs, SRP19 does not engage specific RNA bases through conserved sequence motifs present within β-strands 1 and 3. Instead, SRP19 uses residues both within and flanking β-strand 1 to stabilize the complex through direct and indirect contacts to the phosphate backbone of the tetraloop, leaving the bases of the tetraloop exposed. This, coupled with the fact that SRP19 appears relatively rigid and undergoes only minor changes in structure upon RNA binding, may underlie the molecular basis by which SRP19 functions to initiate SRP assembly.
AB - Protein SRP19 is an essential RNA-binding component of the signal recognition particle (SRP) in Archaea and Eucarya. A three-dimensional solution structure of the 104 residue SRP19 from the hyperthermophilic archaeon Archaeoglobus fulgidus, designated as Af19, was determined by NMR spectroscopy. Af19 contains three β-strands, two α-helical regions, arranged in a βαββα topology, a 310 helix, and a disordered C-terminal tail. This fold is similar to the βαββαβ RNP motif present in numerous other RNA-binding proteins, which engage their cognate RNAs using conserved sequence motifs present within β-strands 1 and 3. Mutagenesis studies of human SRP19, however, reveal the major contact sites with SRP RNA reside within loops 1, 3, and 4. These contacts were verified by the crystal structure of human SRP19 complexed to SRP RNA helix 6 reported subsequent to the submission of the manuscript. The crystal structure also reveals that, unlike canonical RNP motifs, SRP19 does not engage specific RNA bases through conserved sequence motifs present within β-strands 1 and 3. Instead, SRP19 uses residues both within and flanking β-strand 1 to stabilize the complex through direct and indirect contacts to the phosphate backbone of the tetraloop, leaving the bases of the tetraloop exposed. This, coupled with the fact that SRP19 appears relatively rigid and undergoes only minor changes in structure upon RNA binding, may underlie the molecular basis by which SRP19 functions to initiate SRP assembly.
KW - Archaeglobus fulgidus
KW - NMR, RNP
KW - Protein-RNA
KW - SRP19
KW - Signal recognition particle
UR - http://www.scopus.com/inward/record.url?scp=0036290864&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0036290864&partnerID=8YFLogxK
U2 - 10.1006/jmbi.2002.5411
DO - 10.1006/jmbi.2002.5411
M3 - Article
C2 - 11916385
AN - SCOPUS:0036290864
VL - 317
SP - 145
EP - 158
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
SN - 0022-2836
IS - 1
ER -