Molecular cloning of a Chinese hamster mitochondrial protein related to the "chaperonin" family of bacterial and plant proteins.
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.
Picketts
D J
DJ
Department of Biochemistry, McMaster University, Hamilton, Ontario, Canada.
Mayanil
C S
CS
Gupta
R S
RS
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins; D001483:Base Sequence; D002460:Cell Line; D018834:Chaperonin 60; D002850:Chromatography, Gel; D003001:Cloning, Molecular; D006224:Cricetinae; D003412:Cricetulus; D004587:Electrophoresis, Agar Gel; D006360:Heat-Shock Proteins; D006868:Hydrolysis; D015151:Immunoblotting; D008928:Mitochondria / Q000378:metabolism*; D008969:Molecular Sequence Data; D010940:Plant Proteins; D011506:Proteins / Q000378:metabolism*; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid
D001426:Bacterial Proteins; D018834:Chaperonin 60; D006360:Heat-Shock Proteins; D010940:Plant Proteins; D011506:Proteins; D000251:Adenosine Triphosphatases