Unique composition of plastid chaperonin-60: α and β polypeptide-encoding genes are highly divergent

• Published in: Gene Vol. 94; no. 2; pp. 181 - 187
• Main Authors: Martel, Remi, Cloney, Lynn P., Pelcher, Lawrence E., Hemmingsen, Sean M.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 1990; Amsterdam Elsevier; New York, NY
• Subjects: Amino Acid Sequence; Arabidopsis thaliana; ATPase; Bacterial Proteins - genetics; Base Sequence; Biological and medical sciences; Brassica - genetics; Brassica napus; Chaperonins; DNA - isolation & purification; Fundamental and applied biological sciences. Psychology; Fungal Proteins - genetics; Genes. Genome; heat shock; Molecular and cellular biology; Molecular chaperones; Molecular genetics; Molecular Sequence Data; Prokaryotic Cells - drug effects; Proteins - genetics; recombinant DNA; Sequence Homology, Nucleic Acid; aa; cpn-60α; p60 cpn-60m; A; p60 cpn-60; B; p60 cpn-60α; ATPase; nt; cpn-60β; p60 cpn-60β; heat shock; bp; Arabidopsis thaliana; P; Molecular chaperones; Cpn-60; kb; Brassica napus; recombinant DNA; Cpn-10; p10 cpn-10; Nucleotide sequence; Cruciferae; Dicotyledones; Angiospermae; Chloroplast DNA; Homology; Spermatophyta; Molecular cloning
• ISSN: 0378-1119; 1879-0038
• 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 (p60 cpn-60 ). In contrast, preparations of purified plastid Cpn-60 contain approximately equal quantities of two polypeptides, p60 cpn-60α and p60 cpn-60β , with slightly different electrophoretic mobilities. We have isolated cDNA clones encoding plastid p60 cpn-60α and p60 cpn-60β polypeptides from Brassica napus and Arabidopsis thaliana. The unexpected degree of sequence divergence observed between p60 cpn-60α and p60 cpn-60β 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 p60 cpn-60 sequences which resembles the p10 cpn-10 sequences.