Can I make a 455Khz Sine Wave with the Arduino UNO?
The Arduino does not has a DAC (digital analog converter), so you cannot make an output varying in voltage (except for 0V / 5V) by default.

The PWM outputs use 0V/5V with duty cycle but this is not a sine wave. 

So you need additional hardware anyway.

Also, regarding speed if you have a DAC. Assume 16 MHz for the Arduino, having a 455 Khz sinewave, you have about 35 clock cycli per complete sine wave. The sine values you can store in a table, but you need probably at least 3 or 4 clock cycli per sine wave value (to fetch the value from the table and to send it to the DAC), this results in about 8 values which will give a very rough sine wave.

So I would go for a separate sine wave generator.