Even though the trailing underscore trick works, it’s probably best to use a synonym or a multiword name. In the above example, your code will probably look better if you use something like reserved_class to name the argument and the corresponding attribute....
No three-dimensional structure has been solved yet for any RABL2 protein, but their high similarity to other small GTPases, especially Rabs, makes it likely that their tertiary structure and catalytic mechanism will be basically the same. We nevertheless used the broad multiple alignment of RABL2...