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.

[339, 40, 321, 337, 489, 221, 228, 415, 267, 120, 408, 287, 363, 317, 99, 193, 262, 474, 448, 443]
[339, 489, 321, 337, 40, 221, 228, 415, 267, 120, 408, 287, 363, 317, 99, 193, 262, 474, 448, 443]