Sequence analysis to identify the SNP in MtrB sensor kinase.

A. Total SNPs found in the DNA sequence of the mtrAB TCS in the 2501 strains of M. tuberculosis (sequences available in GMTV database). B. A list of nonsynonymous SNPs found in the MtrB protein with the codon changes and their percentage frequencies. C. Sequence alignment of the protein showing the histidine kinase and HATPase domain of the sensor kinase protein MtrB, using H37Rv as the reference strain. The alignment of sequence from H37Rv and one representative strain from GMTV carrying the mutation is shown. SHELR box in the kinase domain is marked in bold and shaded grey with the mutation from Methionine to Leucine at the 517^th residue marked in bold; CS1 is the number assigned to the representative clinical strain used for alignment. D. Pfam based predicted structure of the sensor kinase protein MtrB, highlighting three distinct domains: the HAMP domain, the Histidine Kinase (HK) domain, and the HATPase domain. The mutation at the 517^th position, which lies in the HATPase domain, is marked by the black arrow.