Crystallization and preliminary X-ray analysis of the conserved domain IV of Escherichia coli 4.5S RNA

Acta Crystallogr D Biol Crystallogr. 2000 Aug;56(Pt 8):1033-7. doi: 10.1107/s0907444900006910.


4.5S RNA forms with Ffh protein the prokaryotic signal recognition particle (SRP), a highly conserved ribonucleoprotein complex essential for protein secretion. It also independently binds to elongation factor G (EF-G) in the ribosome and has a function in a subset of translocation events that is transient but required for viability. Crystals of three different constructs encompassing the conserved domain IV of 4.5S RNA, containing the recognition elements for both Ffh and EF-G, were obtained. Native X-ray diffraction data were collected for two crystal forms under cryogenic cooling conditions. The best crystals are of a 45 nt construct, diffract anisotropically to 2.6 A resolution using synchrotron radiation and belong to space group P3(2)21, with unit-cell parameters a = b = 69.1, c = 84.6 A and a single RNA molecule per asymmetric unit.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics
  • Base Sequence
  • Conserved Sequence
  • Crystallization
  • Crystallography, X-Ray
  • Escherichia coli / chemistry*
  • Escherichia coli / genetics
  • Escherichia coli Proteins*
  • Molecular Sequence Data
  • Nucleic Acid Conformation
  • Peptide Elongation Factor G / genetics
  • RNA, Bacterial / chemistry*
  • RNA, Bacterial / genetics
  • RNA, Ribosomal / chemistry*
  • RNA, Ribosomal / genetics
  • Signal Recognition Particle / genetics


  • 4.5S RNA
  • Bacterial Proteins
  • Escherichia coli Proteins
  • Ffh protein, E coli
  • Peptide Elongation Factor G
  • RNA, Bacterial
  • RNA, Ribosomal
  • Signal Recognition Particle