Phytic acid is primarily found in the brans and hulls (the fiber portion) of seeds and grains. The protein is found inside, in the endosperm portion. Plant protein isolates don't have much phytic acid, less than 0.5%. 

Here is a succinct article from Dr. Weil about phytic acid — in it, he states that only individuals who have a diet heavy in wheat bran or lots of grains should be concerned with too much phytic acid. If this is something you are concerned with, we recommend you reaching out to your health care professional!