Abstract: Inha enzyme crystals and methods of growing said crystals are presented. Three crystal forms of the Inha enzyme with discrete unit cell parameters were obtained. The crystals of the Inha enzyme are of sufficient size and quality for x-ray crystallographic determination of the three dimensional structure of the Inha enzyme in concert with heavy atom derivatives of said crystals. With the three dimensional structure of the Inha enzyme, compounds which inhibit the biochemical activity of the Inha enzyme may be developed.

Abstract: The embodiments of the invention are based upon the identification and characterization of genes that determine mycobacterial resistance to the antibiotic isoniazid (INH) and its analogs. These genes, termed inhA, encode a polypeptide, InhA, that is the target of action of mycobacteria for isoniazid. The sequences of wild-type INH-sensitive as well as allelic or mutant INH-resistant inhA genes and their operons are provided. Also provided are isolated InhA polypeptides of both the INH-resistant and INH-sensitive types.

Abstract: Recombinant mycobacterial vaccine vehicles capable of expressing DNA of interest which encodes at least one protein antigen for at least one pathogen against which an immune response is desired and which can be incorporated into the mycobacteria or stably integrated into the mycobacterial genome. The vaccine vehicles are useful for administration to mammalian hosts for purposes of immunization. A recombinant vector which replicates in E. coli but not in mycobacteria is also disclosed. The recombinant vector includes 1) a mycobacterial gene or portions thereof, necessary for recombination with homologous sequences in the genome of mycobacteria transformed with the recombinant plasmid; 2) all or a portion of a gene which encodes a polypeptide or protein whose expression is desired in mycobacteria transformed with the recombinant plasmid; 3) DNA sequences necessary for replication and selection in E. coli; and 4) DNA sequences necessary for selection in mycobacteria (e.g., drug resistance).