Mycobacterium tuberculosis expresses two chaperonin-60 homologs

Proc Natl Acad Sci U S A. 1993 Apr 1;90(7):2608-12. 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 approximately 60-kDa polypeptide.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Antigens, Bacterial / biosynthesis
  • Antigens, Bacterial / genetics*
  • Bacterial Proteins / biosynthesis
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / isolation & purification
  • Base Sequence
  • Chaperonin 60
  • Chromatography, Affinity
  • DNA, Bacterial / genetics
  • DNA, Bacterial / isolation & purification
  • Gene Library
  • Genes, Bacterial*
  • Heat-Shock Proteins / biosynthesis
  • Heat-Shock Proteins / genetics*
  • Heat-Shock Proteins / isolation & purification
  • Molecular Sequence Data
  • Molecular Weight
  • Mycobacterium bovis / genetics
  • Mycobacterium tuberculosis / genetics*
  • Mycobacterium tuberculosis / metabolism
  • Oligodeoxyribonucleotides
  • RNA, Bacterial / genetics
  • RNA, Bacterial / isolation & purification
  • Restriction Mapping
  • Sequence Homology, Amino Acid


  • Antigens, Bacterial
  • Bacterial Proteins
  • Chaperonin 60
  • DNA, Bacterial
  • Heat-Shock Proteins
  • Oligodeoxyribonucleotides
  • RNA, Bacterial

Associated data

  • GENBANK/X60350