By data mining in the sequence of the Corynebacterium glutamicum ATCC 13032 
genome, six putative mycolyltransferase genes were identified that code for 
proteins with similarity to the N-terminal domain of the mycolic acid 
transferase PS1 of the related C. glutamicum strain ATCC 17965. The genes 
identified were designated cop1, cmt1, cmt2, cmt3, cmt4, and cmt5 ( cmt from 
corynebacterium mycolyl transferases). cop1 encodes a protein of 657 amino 
acids, which is larger than the proteins encoded by the cmt genes with 365, 341, 
483, 483, and 411 amino acids. Using bioinformatics tools, it was shown that all 
six gene products are equipped with signal peptides and esterase domains. 
Proteome analyses of the cell envelope of C. glutamicum ATCC 13032 resulted in 
identification of the proteins Cop1, Cmt1, Cmt2, and Cmt4. All six 
mycolyltransferase genes were used for mutational analysis. cmt4 could not be 
mutated and is considered to be essential. cop1 was found to play an additional 
role in cell shape formation. A triple mutant carrying mutations in cop1, cmt1, 
and cmt2 aggregated when cultivated in MM1 liquid medium. This mutant was also 
no longer able to synthesize trehalose di coryno mycolate (TDCM). Since single 
and double mutants of the genes cop1, cmt1, and cmt2 could form TDCM, it is 
concluded that the three genes, cop1, cmt1, and cmt2, are involved in TDCM 
biosynthesis. The presence of the putative esterase domain makes it highly 
possible that cop1, cmt1, and cmt2 encode enzymes synthesizing TDCM from 
trehalose monocorynomycolate.