The codec of your source media file is of no real consequence.
What matters in Sequence creation is the aspect ratio and frame rate.
Be sure that your Sequence settings match your footage by doing this:
Or, right-click a media file and select 'New Sequence From Clip".
How do I choose the right sequence settings?
I don't believe you will be able to export to that codec using Premiere Pro. So even though the file might come in just fine, your export will be something different.