Characterization of the str operon genes from Spirulina platensis and their evolutionary relationship to those of other prokaryotes

Mol Gen Genet. 1989 May;217(1):97-104. doi: 10.1007/BF00330947.


A 5.3 kb DNA segment containing the str operon (ca. 4.5 kb) of the cyanobacterium Spirulina platensis has been sequenced. The str operon includes the structural genes rpsL (ribosomal protein S12), rpsG (ribosomal protein S7), fus (translation elongation factor EF-G) and tuf (translation elongation factor EF-Tu). From the nucleotide sequence of this operon, the primary structures of the four gene products have been derived and compared with the available corresponding structures from eubacteria, archaebacteria and chloroplasts. Extensive homologies were found in almost all cases and in the order S12 greater than EF-Tu greater than EF-G greater than S7; the largest homologies were generally found between the cyanobacterial proteins and the corresponding chloroplast gene products. Overall codon usage in S. platensis was found to be rather unbiased.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Biological Evolution*
  • Cells* / ultrastructure
  • Cloning, Molecular
  • Codon
  • Cyanobacteria / genetics*
  • DNA
  • Molecular Sequence Data
  • Operon*
  • Peptide Elongation Factor G
  • Peptide Elongation Factor Tu / genetics
  • Peptide Elongation Factors / genetics*
  • Plasmids
  • Prokaryotic Cells* / ultrastructure
  • Restriction Mapping
  • Ribosomal Proteins / genetics*
  • Sequence Homology, Nucleic Acid


  • Codon
  • Peptide Elongation Factor G
  • Peptide Elongation Factors
  • Ribosomal Proteins
  • ribosomal protein S12
  • ribosomal protein S7
  • DNA
  • Peptide Elongation Factor Tu

Associated data

  • GENBANK/X15646