Four of the five open reading frames (ORFs) present in Myobacterium fortuitum pAL5000 plasmid (ORF1, ORF3, ORF4, and ORF5) are dispensable for replication in M. fortuitum. However, two additional ORFs (ORF1 and ORF5) were necessary for replication in a Myobacterium smegmatis heterologous host containing an efficient plasmid transformation mutation.