The transfer equation for this circuit (see the following figure) takes the form of Y = -mX + b. The transfer function slope is negative, and the dc intercept is positive. RF and RG are contained in both halves of the equation, thus it is hard to obtain the desired slope and dc intercept without modifying VREF. This is the minimum component count configuration for this transfer function. When the reference voltage is 0, the input voltage is constrained to negative voltages because positive input voltages would cause the output voltage to saturate at ground.
Refer to the following links:
Single-Supply Circuit Circuit Collection Introduction Describing The Split-Supply Topology
Single-Supply Circuit Collection Boundary Conditions
Single-Supply Circuit Collection Amplifiers
