ABSTRACT
The putA gene product is a most interesting multifunctional protein that possesses complex catalytic, binding and regulatory activities. The putA gene product is readily purified from the detergent treated extract by precipitation with ammonium sulfate, desalting on G–50 Sephadex and chromatography on DEAE. The putA mutants define a single complementation group as is expected for a gene encoding a single polypeptide. The putA gene is part of a two-gene cluster which encodes functions necessary for proline utilization. The second gene, putP, encodes the cell’s major proline permease. The reversion of mutations defective for enzymatic activity may uncover mutations which have lost regulatory functions. The oxidase reaction of the putA gene product is dependent on the presence of a membrane-bound electron transport chain which uses oxygen as its terminal electron acceptor. Any autogenously controlled system should have the range of mutant types and reversion patterns seen for the putA gene.
