DNA gyrase, B subunit; A type II topoisomerase that negatively supercoils closed circular double-stranded (ds) DNA in an ATP-dependent manner to modulate DNA topology and maintain chromosomes in an underwound state. Negative supercoiling favors strand separation, and DNA replication, transcription, recombination and repair, all of which involve strand separation. Also able to catalyze the interconversion of other topological isomers of dsDNA rings, including catenanes and knotted rings. Type II topoisomerases break and join 2 DNA strands simultaneously in an ATP-dependent manner.

DNA topoisomerase IV subunit B; Catalyzes the relaxation of negatively supercoiled DNA in the presence of ATP or dATP but not other nucleotides. Individual subunits have no activity. Not able to negatively supercoil DNA, it can however introduce positive supercoils in DNA. Relaxes positive supercoils in an ATP-dependent manner. Catenates and decatenates DNA. Generates dsDNA breaks in the presence of the quinolone antibiotic ciprofloxacin, showing it is a topoisomerase.

DNA-directed RNA polymerase, beta subunit; DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. This subunit often mutates to generate rifampicin (Rif) resistance. Interaction with RbpA partially restores Rif-inhibited transcription; once the subunit is Rif-resistant however RbpA no longer stimulates transcription.

[NADH] enoyl-[acyl-carrier-protein] reductase; Enoyl-ACP reductase of the type II fatty acid syntase (FAS- II) system, which is involved in the biosynthesis of mycolic acids, a major component of mycobacterial cell walls. Catalyzes the NADH-dependent reduction of the double bond of 2-trans- enoyl-[acyl-carrier protein], an essential step in the fatty acid elongation cycle of the FAS-II pathway. Shows preference for long-chain fatty acyl thioester substrates (>C16), and can also use 2-trans-enoyl-CoAs as alternative substrates (By similarity). The mycobacterial FAS-II system utilizes th [...]

Ribosomal protein S12; With S4 and S5 plays an important role in translational accuracy.

DNA-directed RNA polymerase, beta' subunit; DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates.

DNA-directed RNA polymerase, alpha subunit; DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates.

DNA polymerase III, beta subunit; Confers DNA tethering and processivity to DNA polymerases and other proteins. Acts as a clamp, forming a ring around DNA (a reaction catalyzed by the clamp-loading complex) which diffuses in an ATP- independent manner freely and bidirectionally along dsDNA. Initially characterized for its ability to contact the catalytic subunit of DNA polymerase III (Pol III), a complex, multichain enzyme responsible for most of the replicative synthesis in bacteria; Pol III exhibits 3'-5' exonuclease proofreading activity. The beta chain is required for initiation of [...]

Protein RecA; Required for homologous recombination (HR) and the bypass of mutagenic DNA lesions (double strand breaks, DSB) by the SOS response. Can catalyze the hydrolysis of ATP in the presence of single-stranded DNA, the ATP-dependent uptake of single-stranded DNA by duplex DNA, and the ATP-dependent hybridization of homologous single-stranded DNAs. Numerous X-ray crystals have been resolved under different conditions which indicate the flexibility of the protein, essential to its function. Gln-196 contributes to this plasticity by acting as a switch residue, which transmits the ef [...]