The binding mode of the trigger factor on the ribosome: implications for protein folding and SRP interaction.
This study presents the X-ray structure of the N-terminal binding domain of the D. radiodurans trigger factor (TF) in complex with the D. radiodurans large ribosomal subunit. At 3.35 A, a complete description of the interactions with ribosomal proteins L23, L29, and 23S rRNA are disclosed, many of which differ from those found previously for a heterologous bacterial-archaeal TF-ribosome complex. The beta hairpin loop of eubacterial L24, which is shorter in archaeal ribosomes, contacts the TF and severely diminishes the molecular cradle proposed to exist between the TF and ribosome. Bound to the ribosome, TF exposes a hydrophobic crevice large enough to accommodate the nascent polypeptide chain. Superimposition of the full-length TF and the signal-recognition particle (SRP) onto the complex shows that simultaneous cohabitation is possible, in agreement with biochemical data, and suggests a model for the interplay of TF, SRP, and the nascent chain during translation.
Schlünzen
Frank
F
Max-Planck Institute for Molecular Genetics, Ihnestrasse 73, D-14195 Berlin, Germany. Schluenz@molgen.mpg.de
Wilson
Daniel N
DN
Tian
Pingsheng
P
Harms
Jörg M
JM
McInnes
Stuart J
SJ
Hansen
Harly A S
HA
Albrecht
Renate
R
Buerger
Jörg
J
Wilbanks
Sigurd M
SM
Fucini
Paola
P
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology; D001665:Binding Sites; D034301:Deinococcus / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D057927:Hydrophobic and Hydrophilic Interactions; D018832:Molecular Chaperones / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D011485:Protein Binding; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D012269:Ribosomal Proteins / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology*; D018271:Signal Recognition Particle / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology
D001426:Bacterial Proteins; D018832:Molecular Chaperones; D010455:Peptides; D012269:Ribosomal Proteins; D018271:Signal Recognition Particle