The paper presents a highly efficient integrated circuit of a quantum transistor, treated as an atomic-photonic molecule in the form of a linear chain of three microresonators, each of which contains one resonant three-level atom and connects to waveguides for loading and reading photonic qubits. The transistor circuit is scalable and can be used to perform a quantum logic element CNOT with close to unity efficiency for the transfer of a photon qubit between the atoms of the transistor and the reversible loading of a photon qubit into the atoms of resonators.