Escherichia coli 70 S ribosome at 15 A resolution by cryo-electron microscopy: localization of fMet-tRNAfMet and fitting of L1 protein.
Cryo-electron microscopy of the ribosome in different binding states with mRNA and tRNA helps unravel the different steps of protein synthesis. Using over 29,000 projections of a ribosome complex in single-particle form, a three-dimensional map of the Escherichia coli 70 S ribosome was obtained in which a single site, the P site, is occupied by fMet-tRNAfMet as directed by an AUG codon containing mRNA. The superior resolution of this three-dimensional map, 14.9 A, has made it possible to fit the tRNA X-ray crystal structure directly and unambiguously into the electron density, thus determining the locations of anticodon-codon interaction and peptidyltransferase center of the ribosome. Furthermore, at this resolution, one of the distinctly visible domains corresponding to a ribosomal protein, L1, closely matches with its X-ray structure.
Malhotra
A
A
Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY, 12201-0509, USA.
Penczek
P
P
Agrawal
R K
RK
Gabashvili
I S
IS
Grassucci
R A
RA
Jünemann
R
R
Burkhardt
N
N
Nierhaus
K H
KH
Frank
J
J
D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D016616:Cryoultramicrotomy; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000235:genetics; D007091:Image Processing, Computer-Assisted; D008854:Microscopy, Electron; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D010455:Peptides; D011487:Protein Conformation; D012343:RNA, Transfer / Q000378:metabolism; D012358:RNA, Transfer, Met / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure*; D012269:Ribosomal Proteins / Q000737:chemistry* / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism / Q000648:ultrastructure*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D016963:Thermus thermophilus / Q000378:metabolism
D001426:Bacterial Proteins; D010455:Peptides; D012358:RNA, Transfer, Met; D012269:Ribosomal Proteins; C089238:fMet-tRNA(fMet); C028546:ribosomal protein L1; D012343:RNA, Transfer