smegmatis SMR5. B. RT-PCR amplification of Rv1337 cDNA
from MTC, MAC and M. smegmatis mRNA. Lanes: L, 100 bp DNA ladder; 1, M. tuberculosis H37Rv; 2, M. tuberculosis BN44; 3, M. bovis BCG; 4, M. bovis JN55; 5, M. avium; 6, M. avium subsp. Paratuberculosis; 7, M. smegmatis SMR5; 8, negative control (M. tuberculosis mRNA, not reverse transcribed); 9, negative control (E. coli mRNA, reverse transcribed); 10, negative control (water). C: Similar assays as in B showing cDNA Veliparib chemical structure amplification (~350 bp) of the internal fragment of Rv1337 othologs. Negative controls for panel “”A”" (not shown) were similar to 8, 9 & 10. What are the lengths of MTC rhomboids? In genome databases, the lengths for annotated sequences of rhomboids from genetically related mycobacteria vary, and initially we thought this reflected strain diversity. For instance, lengths for Rv0110 orthologs of MTC species are either 249 or 284 residues, while Rv1337 orthologs from the same species are 240 residues. In contrast, MT1378 (ortholog of Rv1337) of M. tuberculosis CDC 1551 is 227 amino acids, 13 residues shorter at the NH2-terminus. Thus, we aimed
to validate the sizes of rhomboids from related strains/species. Genomic analyses at the rhomboid loci for the sequenced MTC genomes revealed that MTC rhomboid orthologs are 100% identical and are of equal length. Rhomboids were PCR-amplified from MTC with common primer sets for each ortholog (see methods), and sequencing data confirmed that MTC rhomboid orthologs Doramapimod supplier are identical and are of the same size (284 residues for Rv0110 orthologs and 240 residues for Rv1337 orthologs). Rhomboid sequences were deposited in GenBank and accession numbers
were assigned (see table 3). Putative gene clusters for mycobacterial rhomboids To determine putative functional coupling between mycobacterial Urease rhomboids and other genes, genes in clusters formed by mycobacterial rhomboids at the KEGG database [51] were analyzed. The gene cluster formed by Rv1337 was conserved across the genus and extended to other actinobacteria such as Norcardia and Corynebacteria. This cluster included 58 genes (Rv1311 to Rv1366, see additional file 5) of which some are essential and others are required for the growth of M. tuberculosis in macrophages [38], a necessary step during pathogenesis of the tubercle bacillus. Conversely, the Rv0110 orthologs formed clusters reflecting the genetic relatedness of mycobacteria. Thus, the orthologs from MTC species and M. marinum formed similar clusters consisting of 61 genes (Rv0080 to Rv0140, see additional file 6). These clusters also included essential genes and those required for survival of the tubercle bacillus in macrophage. However, MUL_4822 of genetically related M. ulcerans was not included in the MTC/M. marinum cluster, and formed a unique cluster consisting of only 19 genes (MUL_4791 to MUL_4824) with two genes upstream of the rhomboid (MUL_4823 and MUL_4824, see additional file 7).