Molecular cloning of a Chinese hamster mitochondrial protein related to the "chaperonin" family of bacterial and plant proteins

J Biol Chem. 1989 Jul 15;264(20):12001-8.


The complete cDNA sequence of a mitochondrial protein from Chinese hamster ovary cells, designated P1, which was originally identified as a microtubule-related protein (Gupta, R.S., Ho, T.K.W., Moffat, M.R.K., and Gupta, R. (1982) J. Biol. Chem. 257, 1071-1078), has been determined. The P1 cDNA encodes a protein of 60,983 Da including a 26-amino acid putative mitochondrial targeting sequence at its N-terminal end. The deduced amino acid sequence of Chinese hamster P1 shows 97% identity to the human P1 protein. Most interestingly, the amino acid sequences of mammalian P1 proteins show extensive sequence homology (42-60% identical residues and an additional 15-25% conservative replacements) to the "chaperonin" family of bacterial, yeast, and plant proteins (viz. groEL protein of Escherichia coli, hsp 60 protein of yeast, and ribulose-1,5-bisphosphate carboxylase subunit binding protein of plant chloroplasts) and to the 60-65-kDa major antigenic protein of mycobacteria and Coxiella burnetii. The homology between mammalian P1 and other proteins begins after the putative mitochondrial presequence and extends up to the C-terminal end. Furthermore, similar to the chaperonin family of proteins, P1 appears to exist in cells as a homooligomeric complex of seven subunits and shows ATPase activity. These observations strongly indicate that P1 protein is a member of the chaperonin family and that it may be involved in a similar function in mammalian cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / metabolism
  • Amino Acid Sequence
  • Animals
  • Bacterial Proteins*
  • Base Sequence*
  • Cell Line
  • Chaperonin 60
  • Chromatography, Gel
  • Cloning, Molecular*
  • Cricetinae
  • Cricetulus
  • Electrophoresis, Agar Gel
  • Heat-Shock Proteins*
  • Hydrolysis
  • Immunoblotting
  • Mitochondria / metabolism*
  • Molecular Sequence Data
  • Plant Proteins*
  • Proteins / metabolism*
  • Restriction Mapping
  • Sequence Homology, Nucleic Acid*


  • Bacterial Proteins
  • Chaperonin 60
  • Heat-Shock Proteins
  • Plant Proteins
  • Proteins
  • Adenosine Triphosphatases

Associated data

  • GENBANK/J04834
  • GENBANK/M22383