Unique composition of plastid chaperonin-60: alpha and beta polypeptide-encoding genes are highly divergent

Gene. 1990 Oct 15;94(2):181-7. doi: 10.1016/0378-1119(90)90385-5.


Molecular chaperones of the chaperonin family occur in prokaryotes and in plastids and mitochondria. Prokaryotic and mitochondrial chaperonin-60 oligomers (Cpn-60) are composed of a single subunit type (p60cpn-60). In contrast, preparations of purified plastid Cpn-60 contain approximately equal quantities of two polypeptides, p60cpn-60 alpha and p60cpn-60 beta, with slightly different electrophoretic mobilities. We have isolated cDNA clones encoding plastid p60cpn-60 alpha and p60cpn-60 beta polypeptides from Brassica napus and Arabidopsis thaliana. The unexpected degree of sequence divergence observed between p60cpn-60 alpha and p60cpn-60 beta raises questions concerning the structure of the oligomer and the functions of these polypeptides. We have also found an amino acid sequence motif within all p60cpn-60 sequences which resembles the p10cpn-10 sequences.

Publication types

  • Comparative Study

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / genetics*
  • Base Sequence
  • Brassica / genetics
  • Chaperonins
  • DNA / isolation & purification
  • Fungal Proteins / genetics*
  • Molecular Sequence Data
  • Prokaryotic Cells / drug effects
  • Proteins / genetics*
  • Sequence Homology, Nucleic Acid


  • Bacterial Proteins
  • Fungal Proteins
  • Proteins
  • DNA
  • Chaperonins

Associated data

  • GENBANK/M35597
  • GENBANK/M35598
  • GENBANK/M35599
  • GENBANK/M35600