Did you install a custom recovery? That will cause the 4.3 OTA to fail. It will also let you flash the SuperSU or koush's superuser zip which should then restore your root access.
I don't have the ability to post a link yet, but if you search for Chainfire's SuperSu, you should find a page on XDA for 1.86. Download the zip to your One, flash it in recovery, and you should have root back!