Mycobacterium tuberculosis Expresses Two Chaperonin-60 Homologs

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 90; no. 7; pp. 2608 - 2612
• Main Authors: Kong, T. H., Coates, A. R. M., Butcher, P. D., Hickman, C. J., Shinnick, T. M.
• Format: Journal Article
• Language: English
• Published: Washington, DC National Academy of Sciences of the United States of America 01.04.1993; National Acad Sciences; National Academy of Sciences
• Subjects: amino acid sequence; Amino acids; Antigens; Antigens, Bacterial - biosynthesis; Antigens, Bacterial - genetics; Bacterial Proteins - biosynthesis; Bacterial Proteins - genetics; Bacterial Proteins - isolation & purification; Bacteriology; Base Sequence; Biological and medical sciences; Chaperonin 60; Chromatography, Affinity; DNA, Bacterial - genetics; DNA, Bacterial - isolation & purification; expression; Fundamental and applied biological sciences. Psychology; Gels; Gene Library; Genes; Genes, Bacterial; Genetics; Heat-Shock Proteins - biosynthesis; Heat-Shock Proteins - genetics; Heat-Shock Proteins - isolation & purification; Microbiology; Molecular Sequence Data; Molecular Weight; Mycobacterium bovis - genetics; Mycobacterium tuberculosis; Mycobacterium tuberculosis - genetics; Mycobacterium tuberculosis - metabolism; nucleotide sequence; Nucleotide sequences; Oligodeoxyribonucleotides; Open reading frames; Plasmids; predictions; Proteins; Restriction Mapping; RNA; RNA, Bacterial - genetics; RNA, Bacterial - isolation & purification; Sequence Homology, Amino Acid; Tuberculosis; Chaperonin; Purification; Chaperone; Homology; Primary structure; Gene expression; Antigen; Gene; Mycobacterium tuberculosis; Mycobacteriales; Heat shock protein; Mycobacteriaceae; Bacteria; Actinomycetes
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.90.7.2608

A 65-kDa protein and a 10-kDa protein are two of the more strongly immunoreactive components of Mycobacterium tuberculosis, the causative agent of tuberculosis. The 65-kDa antigen has homology with members of the GroEL or chaperonin-60 (Cpn60) family of heat shock proteins. The 10-kDa antigen has homology with the GroES or chaperonin-10 family of heat shock proteins. These two proteins are encoded by separate genes in M. tuberculosis. The studies reported here reveal that M. tuberculosis contains a second Cpn60 homolog located 98 bp downstream of the 10-kDa antigen gene. The second Cpn60 homolog (Cpn60-1) displays 61% amino acid sequence identity with the 65-kDa antigen (Cpn60-2) and 53% and 41% identity with the Escherichia coli GroEL protein and the human P60 protein, respectively. Primer-extension analysis revealed that transcription starts 29 bp upstream of the translation start of the Cpn60-1 homolog and protein purification studies indicate that the cpn60-1 gene is expressed as an ≈60-kDa polypeptide.