Given the task definition and input, reply with output. In this task, you are given a list of unique integers you need to swap the positions of maximum and minimum element in the list and return the updated list.

[157, 298, 54, 206, 237, 485, 440, 282, 247, 450, 28, 280, 474, 496, 379, 390, 392, 217, 422, 165]

[157, 298, 54, 206, 237, 485, 440, 282, 247, 450, 496, 280, 474, 28, 379, 390, 392, 217, 422, 165]