Most of the phylogenies are those of ß-lactamases, the enzymes tht are primarily responsible for resistance to ß-lactam antibiotics sumch as penicillin and its relatives. ß-lactamases fall into two unrelated groups that, although they act on many of the same substrates, catalyze the hydrolysis of ß-lactam bonds by completely different mechanisms. Click the Serine ß-lactamases or the Metallo-ß-lactamases buttons in the navigation bar to see more detail on those groups. Within each group are Classes whose homology can only be detected at the protein structural level. Within each class homology of the proteins can be detected at the sequence level. The Structural Phylogeny buttons show the relationships among or between the Classes, and the individual Class Phylogeny buttons show the relationships of individual sequences within the classes.

There are also a wide variety of enzymes that inactivate aminoglycoside antibiotics such as kanamycin. At this time phylogenies of only one catergory of those enzymes, the Aminoglycoside-6'-acetyl-transferases [AAC(6')], is avaialbe on the Other Phylogenies page. Other phylogenies may be added to that page in the future.

The individual phylogenies pages allow you to view and to download the phylogenies and to download the papers in which those phylogenies were published.