A Mycobacterium tuberculosis operon encoding ESAT-6 and a novel low-molecular-mass culture filtrate protein (CFP-10)

Microbiology (Reading). 1998 Nov;144 ( Pt 11):3195-203. doi: 10.1099/00221287-144-11-3195.


The early secreted antigenic target 6 kDa protein (ESAT-6) is a potent T-cell protein antigen synthesized by Mycobacterium tuberculosis. Its corresponding gene (esat-6) is located in RD1, a 10 kb DNA region deleted in the attenuated tuberculosis vaccine strain Mycobacterium bovis BCG. The promoter region of M. tuberculosis esat-6 was cloned and characterized. A new gene, designated lhp and cotranscribed with esat-6, was identified. Moreover, computer searches in the M. tuberculosis genome identified 13 genes related to the lhp/esat-6 operon, defining a novel gene family. The transcription initiation sites of the lhp/esat-6 operon were mapped using M. tuberculosis RNA. The corresponding promoter signals were not recognized in Mycobacterium smegmatis, in which transcription of lhp/esat-6 is initiated at different locations. The M. tuberculosis lhp gene product was identified as CFP-10, a low-molecular-mass protein found in the short-term culture filtrate. These results show that the genes encoding CFP-10 and ESAT-6 are transcribed together in M. tuberculosis and that both code for small exported proteins.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Antigens, Bacterial / genetics*
  • Antigens, Bacterial / metabolism
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / metabolism
  • Base Sequence
  • Chromosome Mapping
  • Cloning, Molecular
  • Lac Operon
  • Molecular Sequence Data
  • Multigene Family
  • Mycobacterium tuberculosis / genetics*
  • Operon / genetics*
  • Promoter Regions, Genetic
  • Recombinant Fusion Proteins / metabolism
  • Transcription, Genetic


  • Antigens, Bacterial
  • Bacterial Proteins
  • CFP-10 protein, Mycobacterium tuberculosis
  • ESAT-6 protein, Mycobacterium tuberculosis
  • Recombinant Fusion Proteins

Associated data

  • GENBANK/AF004671