Genomics and Proteomics of Mycobacteriophage Patience, an Accidental Tourist in the Mycobacterium Neighborhood

Pope, Welkin H.; Jacobs-Sera, Deborah; Russell, Daniel A.; Rubin, Daniel H. F.; Kajee, Afsana; Msibi, Zama N. P.; Larsen, Michelle H.; Jacobs, William R.; Lawrence, Jeffrey G.; Hendrix, Roger W.; Hatfull, Graham F.

There is also substantial variation in tRNA content of the mycobacteriophages. Many have no tRNA genes, and some have only one or a small number, while others-such as the members of clusters C and M-have more than 20 (7, 8) . The rationale for carriage of these is unclear, and there is no obvious correlation between tRNA content and percent GC that might reflect tRNA acquisition to augment gene expression in newly acquired hosts. It has been noted that there is no close correlation between the tRNA specificities encoded by D29 and infrequently used codons (9) or between Bxz1 and phage codon preferences of putative highexpression genes (10) . Analysis of the codon usage of 32 mycobacteriophage genomes showed that there is variation in codon usage preferences (11) . In some phage genomes, the tRNAs may counteract host measures to protect themselves from infection by tRNA destruction (12) .