PMID- 6170632
OWN - NLM
STAT- MEDLINE
DCOM- 19820109
LR  - 20190511
IS  - 0021-924X (Print)
IS  - 0021-924X (Linking)
VI  - 90
IP  - 2
DP  - 1981 Aug
TI  - Conformational studies of Escherichia coli ribosomes with the use of acridine 
      orange as a probe.
PG  - 449-61
AB  - The interaction of E. coli vacant ribosomes with acridine orange (AO) was 
      studied, to obtain conformational information about rRNAs in ribosomes. Acridine 
      orange binds to an RNA in two different modes: cooperative outside binding with 
      stacking of bound AO's and intercalation between nucleotide bases. Free 16S and 
      23S rRNAs have almost identical affinities to AO. At 1 mM Mg2+, AO can achieve 
      stacking binding on about 40% of rRNA phosphate groups. The number of stacking 
      binding sites falls to about 1/3 in the 30S subunit in comparison with free 16S 
      rRNA. In the 50S subunit, the number of stacking binding sites is only 1/5 in 
      comparison with free 23S rRNA. Mg2+ ions are more inhibitory for the binding of 
      AO to ribosomes than to free rRNAs. The strength of stacking binding appears to 
      be more markedly reduced by Mg2+ in active ribosomes than in rRNAs. "Tight 
      couple" 70S particles are less accessible for stacking binding than free 
      subunits. The 30S subunits that have irreversibly lost the capability for 70S 
      formation under low Mg2+ conditions have an affinity to AO that is very different 
      from that of active 30S but similar to that of free rRNA, though the number of 
      stacking binding sites is little changed by the inactivation. 70S and 30S 
      ribosomes with stacking bound AO's have normal sedimentation constants, but the 
      50S subunits reversibly form aggregates.
FAU - Horie, K
AU  - Horie K
FAU - Wada, A
AU  - Wada A
FAU - Fukutome, H
AU  - Fukutome H
LA  - eng
PT  - Journal Article
PL  - England
TA  - J Biochem
JT  - Journal of biochemistry
JID - 0376600
RN  - 0 (Phosphates)
RN  - 0 (RNA, Bacterial)
RN  - 0 (RNA, Ribosomal)
RN  - F30N4O6XVV (Acridine Orange)
RN  - I38ZP9992A (Magnesium)
SB  - IM
MH  - Acridine Orange/*metabolism
MH  - Centrifugation, Density Gradient
MH  - Dose-Response Relationship, Drug
MH  - Escherichia coli/*metabolism
MH  - Magnesium/pharmacology
MH  - Nucleic Acid Conformation
MH  - Phosphates/metabolism
MH  - RNA, Bacterial/metabolism
MH  - RNA, Ribosomal/*metabolism
MH  - Ribosomes/drug effects/*metabolism
MH  - Spectrum Analysis
EDAT- 1981/08/01 00:00
MHDA- 1981/08/01 00:01
CRDT- 1981/08/01 00:00
PHST- 1981/08/01 00:00 [pubmed]
PHST- 1981/08/01 00:01 [medline]
PHST- 1981/08/01 00:00 [entrez]
AID - 10.1093/oxfordjournals.jbchem.a133492 [doi]
PST - ppublish
SO  - J Biochem. 1981 Aug;90(2):449-61. doi: 10.1093/oxfordjournals.jbchem.a133492.