Sequence alignment of 27 open reading frames belonging to the 19 kDa family. Highly conserved cysteine, and phenylalanine residues are highlighted. "*" indicates fully conserved positions; ":" indicates strong conservation; "." Indicates weaker conservation. The 0-glycosylated threonine residues in the M. tuberculosis LpqH are boxed. Fully compliant Lipobox acylation motifs are underlined.