Figure 2

Orthologous mbtH -like gene ( gplH )-nonribosomal peptide synthetase gene loci involved in GPL production.^§ Nucleotide sequence accession numbers (GenBank) of analyzed sequences, protein accession numbers (PAN), available genomic locus tags (GLT), and gene names are shown. Underlined gene names are proposed herein. ^¥M. smegmatis sequence submission AY439015.3 shows a single gene (mps1) where the annotated complete genome (GenBank: CP000480.1) shows two contiguous genes (MSMEG_0400 and MSMEG_0401). Our sequence comparison revealed that CP000480.1 has an insertion of a “C” and a deletion of an “A” relative to AY439015.3. The events (112-bp apart) create a transient frameshift that splits mps1 into MSMEG_0400 and MSMEG_0401. We resequenced the region containing the discrepancies and found that our sequence matched that of AY439015.3. Based on this and the conservation of mps1 across species, we conclude that the correct gene organization is as shown herein. ^†The open reading frame corresponding to this gene has not been previously annotated. ^‡Our sequence analysis (not shown) indicates that the pstA appears to have originated from an mps1 and mps2 deletion-fusion rearrangement relative to the canonical mps1 and mps2 seen in M. avium strains 104 and 2151 and other GPL-producing species. This rearrangement leads to a gene encoding a 4,027-amino acid protein that appears to have segments derived from both Mps1 and Mps2. This protein would not be competent for D-Phe-D-alloThr-D-Ala-L-alaninol synthesis, a defect that alone would explain the known GPL-deficiency of M. avium subsp. paratuberculosis K-10.