Before computing recurrence scores for genes or modules, we calculated the similarity of all gene lists to derive groups of gene lists. Gene lists in the same group could then be collectively down-weighted in the recurrence scoring. The identification of these gene list groups is described next. DNA is a dynamic molecule and is constantly exposed to various types of damaging agents such as mutagenic chemicals, radiation and reactive oxygen. A number of DNA repair systems exist which specialize in the repair of certain types of damage. Nucleotide excision repair is a highly conserved pathway involved in repair of a wide variety of structurally unrelated DNA lesions. One of the well characterized NER systems is the UvrABC nuclease from E. coli. NER consists of two related sub-pathways; global genomic repair, which removes lesions from the overall genome, and transcription coupled repair, which removes lesions from the transcribed strand of active genes. Bulky DNA lesions such as cyclo pyrimidine photodimers induced by UV irradiation block RNA polymerase during transcription. In bacteria a product of mfd called transcription repair coupling factor or Mfd protein is required for TCR. Bacterial Mfd interacts with the stalled RNA polymerase, displaces it from the DNA and recruits NER proteins at the site of damage. Mfd thus clears the steric hindrance from the site of damage and loads UvrA protein, resulting in,10-fold faster repair of the transcribed strand compared to the non-transcribed strand for similar kind of lesions. In addition, Mfd rescues arrested or backtracked transcription elongation complexes by promoting forward translocation of RNA polymerase in ATP dependent manner leading to productive elongation. Additionally, Mfd can release the RNA polymerase when the enzyme cannot continue elongation. Apart from DNA repair, Mfd has other physiological roles in regulation of gene expression, including carbon catabolite repression in Bacillus subtilis and transcription termination by bacteriophage HK022 Nun protein. A key role for Mfd as an enhancer of UvrA turnover in E. coli cells has also been recently demonstrated. The well characterized Mfd from E. coli is a 130 kDa monomeric protein having modular architecture specialized for different functions. The N-terminal domain shares a high degree of structural homology with UvrB protein of NER pathway. The NTD is known to interact with UvrA protein, which is molecular matchmaker of NER pathway, and this interaction is responsible for enhanced rates of repair. The central portion of Mfd consists of RNA polymerase interacting domain which binds to b subunit of RNA polymerase. The C-terminal domain of Mfd harbors seven signature motifs of super-family 2 helicases including ATPase motifs. In addition, CTD contains a TRG motif required for translocation along the DNA. TRG motif as the name implies, is highly homologous to RecG protein, which is known to be involved in branch migration of Holliday junctions during recombination. Pathogenic bacteria continuously encounter multiple forms of stress in their hostile environments, which leads to DNA damage. Genes involved in DNA repair and recombination may play an important role in the virulence of pathogenic organisms. M. tuberculosis is a gram positive, acid fast bacterium and one of the most formidable human pathogen. DNA repair pathways in mycobacteria appear to be crucial for their survival at different stages of infection. Sequencing of M. tuberculosis genome revealed the presence of NER associated genes including a putative mfd. In this work, we describe the functional characterization of MtbMfd and discuss its unusual properties. This is the first detailed analysis of the biochemical Ginsenoside-F4 properties of Mfd from actinomycetes and more importantly from a human pathogen. Limited proteolysis is often employed to determine the domainal organization, stability and Folinic acid calcium salt pentahydrate conformational changes within the protein. The hexamer and monomer fractions of MtbMfd obtained by gel filtration chromatography were subjected to limited digestion by trypsin.