Alignment of MptpB related sequences. Alignment of MptpB related sequences identified from a Blast analysis with one representative sequence from each group in the phylogenetic tree and the sequences of the proteins characterised biochemically in this study, Lm800, Lm1935 and LM1 (the complete alignment is in the Additional file 1). The alignment highlights that the sequences are highly divergent except from the phosphate-binding loop (P-loop) in the active site region with an extended signature (C4). There are additional regions of high conservation (labelled C1-C5). Insertions 1 and 2 are unique to the mycobacteria sequences. Alignment prepared using ClustalX .