Molecular Genetics and Genomics ....
You have joined a lab that has successfully cultured in the laboratory the first bacterium from Mars and you have determined its genetic material is DNA and that it has the major biochemical components (proteins, nucleic acids, carbohydrates, lipids) in approximately similar amounts as bacterial (not archaeal) life on earth. The sequence of the genome has been determined (this was easy, right?), but nothing further is known about this bacterium.
What is the next thing you most want to know about your bacterium? What one experiment will you do first to address your question?